CHAPTER XIV.Reptiles and Batrachians.

CHAPTER XIV.Reptiles and Batrachians.Ina memoir on the Reptiles and Batrachians of the Solomon Islands, which was read before the Zoological Society, on May 6th, 1884,[439]Mr. Boulenger remarked that very little was known about the herpetology of these islands until two important collections, which I sent to the British Museum in 1883 and 1884, brought to light several new and interesting forms, such as could hardly have been expected from this region. “The position of this group of islands on the limits of two great zoological districts,”—this author proceeded to observe—“renders the study of its fauna of special interest, as it is the point where many of the Papuasian and Polynesian forms intermingle. Curiously, all the Batrachians belong to species not hitherto found elsewhere, and one of them is even so strongly modified as to be the type of a distinct family.”[439]Published in the Transactions of the Society; vol. xii., part i., 1886. The diagnoses of most of the new species in my collections were given in the Proceedings for 1884: p. 210. Vide also “Annals and Magazine of Natural History” (5) xii., 1883.According to Mr. Boulenger, the Reptiles may be grouped under four headings, viz.:—1. Species belonging to both the Papuasian and Polynesian districts.2. Indo-Malayan or Papuasian species, not extending further east or south-east.3. Polynesian species, not extending further north and west than New Ireland.4. Species not hitherto found elsewhere than in the Solomons (and New Ireland.)1Gymnodactylus pelagicusGehyra oceanicaMabuia cyanuraPlaturus fasciatus.2Crocodilus porosusGecko vittatusVaranus indicusKeneuxia smaragdinaEnygrus carinatusDipsas irregularis.3Gonyocephalus godeffroyiMabuia carteretiiMa„uianigraEnygrus bibronii.4Lepidodactylus guppyi,n. sp.Lipinia anolis,n. sp.Corucia zebrataDendrophis solomonisHoplocephalus par,n. sp.All of these 19 Reptiles were included in my collection, with the exception ofCorucia zebrata, which, however, came under my observation. I will now proceed to refer more particularly to the Reptile-fauna of this region.Crocodiles.—The species of Crocodile (Crocodilus porosus, Schneid), which is so common in the Solomon Group, ranges from India and South China through the Malay Archipelago and Papuan Islands to North Australia. In these islands crocodiles appear to frequent in greatest numbers the swamps and sandy shores of uninhabited coral islands, such as those of the Three Sisters, and the coasts of the larger islands in the vicinity of the mouths of the streams and rivers. I frequently surprised them basking on the sand under the shade of a tree. On one occasion I was standing on the spreading roots of a tree that were exposed on the beach, when one of these reptiles darted out from under my feet and dived into the sea. Of the marks that they make on the sand when lying at rest, an oblong shallow impression corresponding to the head, and a curved well-defined grove caused by the tail are alone specially recognisable. When they are not alarmed and move leisurely along,they leave a double row of footprints on the sand, with a narrow median furrow produced by the weight of the tail; but when they have been disturbed and make a rush to escape, they raise their tail and leave only the tracks of their feet on the sand. These crocodiles are equally at home in salt and fresh water. I have frequently passed them in my Rob Roy canoe when they have been floating as though asleep at the surface of the sea; and it was always in the sea that they found a refuge when my little craft intruded itself within their haunts. They came under my notice in the fresh-water lakes of Santa Anna and Stirling Island, and in the lower courses of the streams in several localities. They are apparently in no uncongenial conditions in the salt-water lagoon of Eddystone Island, although its waters receive the hot sulphureous vapours of submerged fumaroles.These crocodiles do not apparently attain a greater length than 12 or 13 feet. Mr. Sproul shot one at Santa Anna which measured 91⁄2feet. A female that I shot in the Shortland Islands, measured 11 feet. One of the seamen of the “Lark,” named Prior, obtained from the natives the skull of a rather larger specimen. Out of half-a-dozen individuals seen on the Three Sisters, not one measured more than 7 or 8 feet.[440]Mr. Bateman, a trader resident at Ugi, told me that at Wano on the St. Christoval coast he saw a very large crocodile which, from his description, appears to have been twice as long as any that I saw. It was, however, dusk at the time; and in connection with this circumstance I should add that I have found actual measurement to reduce the apparent length of a crocodile from 14 to 11 feet.[440]A skull given to me by Mr. Nisbet, the government-agent of the “Redcoat,” at Ugi, was 12 inches long. It was obtained from the natives of Guadalcanar.Natives are rarely attacked by these reptiles, and they show little or no fear of them. I have seen a full-grown crocodile dart under a line of swimmers without causing any dismay. Of the numbers I saw, all were but too anxious to get out of my way; and their cowardly nature is well shown in the account of my capture of a specimen which is given below. However, I came upon a man of Santa Anna who had had his leg broken by one of these reptiles. The natives of Rubiana hold the crocodile in veneration and work without fear in the places which it frequents. They believe that only faithless wives are seized and carried off by the monster. Pigs are occasionally the prey of the crocodile;but its usual diet appears to be opossums (Cusci), large lacertilians, and fish.The following account of the capture of a crocodile may interest some of my readers. It was effected by no more formidable weapons than by a number of long staves and a small “bull-dog” revolver. Accompanied by six natives I was making the ascent of a large stream on the north-west side of Alu, when some of my companions espied a large crocodile at the bottom of a deep pool about 200 yards from the mouth of the stream. In setting to work to effect its capture my men proceeded very methodically to work, and evidently knew the tactics which the creature would employ. Standing in the water just below the pool, we stood awaiting the descent of the crocodile down the stream, whilst one of the natives was rousing it up with a long pole to make it leave its hiding-place. After a little time it began to get uneasy, and leaving the pool began to descend the stream. Where we were standing, the stream was only knee-deep, and as the reptile passed us in the shallow water some natives hit it on the head with their poles, whilst others hurled their poles sharpened at the ends, striking it in several places, and I planted a bullet behind its neck. The creature showed no fight and immediately hid itself in the pools near the mouth of the stream. During two hours, after we had been driving it from one pool to another by means of our pointed poles and staves, we seemed no nearer to its capture. At length there was a loud out-cry from the natives. The crocodile was making a final rush for life to cross the bar at the mouth of the stream and escape into the sea. We all followed, some in the canoe and some through the water; and for a short time I thought that the creature would escape. But being a little disabled by our previous attacks, its progress across the bar was somewhat checked; and the foremost of my men caught hold of its tail just as it was getting into deep water. Very quickly we all came up, and assisted in drawing it high and dry on the beach; and whilst two of our number kept hold of its tail, the remainder belaboured its neck with rocks and sticks until it died.[441]Its length proved to be 11 feet. Throughout the whole chase the reptile made no outcry, and even when we were belabouring it to death it only gave a kind of growl. In its stomach I found a large quantity of partially digested foodwith the remains of an opossum (Cuscus) and a large lizard 11⁄2feet long (probablyCorucia zebrata). It was a female, and, in the oviduct I came upon an egg, which my natives appropriated, saying that it was very good food; but they do not usually eat the flesh. I was unable from want of space to keep more than the head of the animal, which I cut off and carried back in my canoe to the ship. The skull is now in the British Museum.[441]An illustration in Mr. Bates’ “Naturalist on the Amazons” represents a very similar scene.Lizards.The Lacertilians are well represented in these islands. Those at present described are given in the subjoined list.GeckonidæGymnodactylus pelagicusGehyra oceanicaLepidodactylus guppyi.n. sp.Gecko vittatusGe„kovar. bivittatus.AgamidæGonyocephalus godeffroyi.VaranidæVaranus indicus.ScincidæMabuia carteretiiMa„uiacyanuraMa„uianigraKeneuxia smaragdinaLipinia anolisn. sp.Corucia zebrata.The lizards, which most frequently meet the eyes of the visitors in the vicinity of the beaches, are the two skinks,Mabuia nigraandcyanura. As a rule those species that are common at the coast have a wide range, extending either into Polynesia or Papuasia or into both these regions (videpage 307). The species peculiar to these islands came less frequently under my observation. Thus, that ofLepidodactylus guppyi, is founded on a single (female) specimen I found in Faro or Fauro Island in Bougainville Straits.Corucia zebratanever came under my notice alive; it is said at Ugi to find its home in the foliage of the higher trees. Doubtless if I could havepenetrated to the higher regions of the large islands, I should have obtained a large number of new species. My collections refer for the most part to the sea-border and its vicinity. In the elevated interior of such an island as Guadalcanar there isa region of great promisefor the collector; but I shall have a further occasion to refer to this topic.The Monitor,Varanus indicus, may be often seen at the coast, basking in the glare of the mid-day sun on the trunks of prostrate trees or on the bare rocks. It is considered edible by the natives of Bougainville Straits. Whilst we were anchored at Oima Atoll, Lieutenant Leeper captured a very large specimen (5 feet 73⁄4inches long)[442]on the rocks close to the sea, and towed it off alive to the ship. After we had tried in vain to strangle it by a cord, a lead was fastened to it and it was sunk overboard, but an hour passed before we could say that the reptile was really dead. This Monitor is probably able to swim considerable distances. It very likely owes its wide range (from Celebes to the Solomon Group including Cape York) to the agency of floating trees. On examining the stomach and intestines, I found them empty. An enormous quantity of fat, developed in two large lobes in connection with theomentumor some other part of theperitoneum, almost filled the abdominal cavity. With this store of sustenance and heat, these reptiles must be able to live without food for a long time.[443][442]A specimen shot in the Florida Islands measured 3 feet 8 inches.[443]As an instance of the tenacity of life that some reptiles possess, I may refer to the case of a young terrapin which I kept inadvertently for nearly five months on the coast of China without any sustenance except the dry rust of a tin can.Snakes.Hitherto, the following six species of Ophidians have been found in the Solomon Group. All of them were included in my collection and one of them has been described by Mr. Boulenger as a new species.BoidæEnygrus carinatusEny„rusbibroniiColubridæDendrophis solomonisDipsas irregularisElapidæHoplocephalus parn. sp.Hydrophiidæ(Water-snakes)Platurus fasciatus[444][444]I was indebted to Lieutenant Symonds of H.M.S. “Diamond” for this snake.One of the commonest of snakes throughout these islands isEnygrus carinatus, a harmless species of the Boa family. It often possesses considerable bulk in proportion to its length. One specimen which I obtained in Treasury Island measured 31⁄2feet in length and 6 inches in girth. I handled a good many living snakes whilst in these islands, since the natives used to bring them in numbers to me both on board and on shore. The statements of the natives and of the white men resident in this region and the general appearance of the snakes had led me to believe that there were no poisonous species in the group. I was therefore somewhat surprised when, on my arrival in England, I learned from Dr. Günther that I had found a new species as poisonous as the Cobra. On being shown the specimen by Mr Boulenger, I at once recognised an old friend which had been brought on board in a bamboo by the natives at Faro Island and had got loose on the deck. Whilst the men standing round were preparing to kill it with more regard for their own safety than for my feelings, I caught it quickly around the neck and held it under water until it was dead. The natives certainly were not aware of its venomous character, nor was Mr. Isabell, who was my right-hand man in these matters, and used to manage the ticklish progress of removing the snakes from their bamboo-tubes in a manner only suitable in the case of harmless species. I only obtained one specimen of this snake, which was about 21⁄2feet in length. It is namedHoplocephalus parand belongs to theElapidæ, a family of poisonous colubrine snakes which possess the physiognomy of the harmless snakes of the same sub-order, and include the Indian and African Cobras with other well known venomous species. In the footnote I have quoted Mr. Boulenger’s description of its general appearance for the information of those who visit the group.[445][445]The upper surface of the head is uniform blackish brown. The body is crossed above by broad red-brown bands separated by narrow white interspaces. The lower surface of the head and body are uniform white, except on the posterior extremity of the body where the red and black extend as lines along the sutures of the ventral shields. On the tail the red forms complete rings. Nearly every one of the dorsal scales have a blackish brown border. The head is depressed, moderately large, and slightly widened posteriorly. The eye has a vertical pupil.Batrachians.—The Spanish discoverers in 1567 remarked that the natives of Isabel worshipped the toad (videpage 203), and one of the officers of Surville’s expedition in 1769, described in his journal a remarkable toad from the same island;[446]yet it is only within recent years that any Batrachians have been collected in this region. Before I arrived in the group only two species were known to science, and to this number my collections, which were made in the islands of Bougainville Straits, have added seven new species, including a type of a new family. The following list represents the Batrachian fauna of the Solomon Islands, as far as it is at present known:[446]“Discoveries of the French in 1768 and 1769,” &c., by M. Fleurieu: London, 1791; p. 134.Ranidæ.Rana buboniformis,n. sp.Rana guppyi,n. sp.Rana opisthodon,n. sp.Rana krefftii.Cornufer guppyi,n. sp.Cornufer solomonis,n. sp.Ceratobatrachidæ.(New family characterised by both jaws being toothed, and by the diapophyses of the sacral vertebra not being dilated.)Ceratobatrachus guentheri,n. sp.Hylidæ(Tree-frogs.)Hyla macrops,n. sp.Hyla thesaurensis.The natives of the islands of Bougainville Straits, where, as I have just remarked, my batrachian collection was chiefly made, have given frogs the general name of “appa-appa” in imitation of their noise, just as they have named the smaller lizards “Kurru-rupu” for the same reason. Amongst the particular species of frogs, I may refer to the large toad-likeRana buboniformis, which I found in Treasury Island, and on the highest peak of the island of Faro.Rana guppyi, according to Mr. Boulenger’s report, attains a larger size than anyother species of the genus, with the exception of the Bull-Frog of North America.Rana opisthodonaffords an instance of a Batrachian[447]which dispenses with the usual larval or tadpole stage, “the metamorphoses being hurried through within the egg.” On this subject I made the following notes. Whilst descending from one of the peaks of Faro Island, I stopped at a stream some 400 feet above the sea, where my native boys collected from the moist crevices of the rocks close to the water a number of transparent gelatinous balls rather smaller than a marble.[448]Each of these balls contained a young frog about 4 lines in length, apparently fully developed, with very long hind legs and short fore legs, no tail, and bearing on the sides of the body small tufts of what seemed to be branchiæ. On my rupturing the ball or egg in which the little animal was doubled up, the tiny frog took a marvellous leap into its existence and disappeared before I could catch it. When I reached the ship an hour after, I found that some of the eggs which had been carried in a tin had been ruptured on the way by the jolting, and the liberated frogs were leaping about with great activity. On placing some of them in an open bottle 8 inches high, I had to put the cover on as they kept leaping out. Mr. Boulenger remarking on this observation says, that there are no gills, but that on each side of the abdomen there are regular transverse folds (with an arrangement like that of the gill-openings of Plagiostomous Fishes), the function of which probably is that of breathing-organs. The tip of the snout is, he says, furnished with a small conical protuberance, projecting slightly through the delicate envelope of the egg, and evidently used to perforate that covering. In the instance also ofCornufer solomonis, another new species included in my collection, Mr. Boulenger remarks that there is every reason to believe that the young undergo the metamorphoses within the egg.[447]Hylodes martinicensis affords another instance. Mon. Berl. Ac., 1876, p. 714.[448]According to Mr. Boulenger, they measure from 6 to 10 mm. in diameter.With regard to the interesting species,Ceratobatrachus guentheri, which forms the type of a new family,Ceratobatrachidæ, the same writer observes that it is remarkable for the numerous appendages and symmetrical folds which ornate its skin. It is, in fact, “all points and angles,” and may be truly termed a horned frog. There is great variation both in the coloration and in the integuments. “Out of the twenty specimens before me,” thus Mr. Boulenger writes, “no two are perfectly alike.” The development is presumedto be of the type in which the metamorphoses are hurried through within the egg. These horned frogs are very numerous in the islands of Bougainville Straits, and so closely do they imitate their surroundings, both in colour and pattern, that on one occasion I captured a specimen by accidentally placing my hand upon it when clasping a tree.It is particularly important to notice not only that the Batrachians of the Solomon Islands, as far as we at present know, do not occur elsewhere, but also that in this region a distinct family has been produced. These facts support the conclusions deducible from the geological evidence that these islands are of considerable geological age (videpage x.). The insular and isolated conditions have been preserved during a period sufficiently extended for the development of a peculiar Batrachian fauna.The modes of dispersal of frogs and toads, and, in truth, of the whole Batrachian class, are matters of which we are to a great extent ignorant. Frogs are usually stated to be absent from oceanic islands, a peculiarity of distribution which apparently accords with the circumstance that neither they nor their spawn can sustain submersion in sea-water. The occurrence, however, of three species ofCornuferin the Caroline and Fiji Islands, and of a species ofBatoin the Sandwich Islands,[449]affects the general application of this conclusion. It may be suggested that these exceptions are due to human agency; but if so, it is difficult to understand why they have not been found in such a well explored island as New Caledonia.[450][449]Boulenger’s “Catalogue of the Batrachia Gradientia,” &c., 2nd edit., 1882.[450]Perhaps the peculiar geographical distribution of the Batrachia may throw light on this subject.Ibid.In concluding this chapter I will refer to the circumstance that my collections of the Reptiles and Batrachians of this large group have only in a manner broken ground in a region which promises the richest results to the collector. It cannot be doubted that in the elevated interiors of the large islands, such as those of Bougainville and Guadalcanar, there will be found a peculiar Reptilian and Batrachian fauna, the study of which will be of the highest importance for the furtherance of our knowledge of these geologically ancient classes of animals. I believe I am correct in stating that it was on account of the highly interesting Batrachian collections I sent to the British Museum, that I received a grant for further exploration from the Royal Society, which, however, I was unfortunatelyprevented from turning to account. The work has yet to be done, and there can be little doubt that the man who is first able to examine the lofty interior of such an island as Guadalcanar will bring back collections, the importance of which will amply recompense him for any hardship or personal risk he may have endured. My experience was confined to the sea-border and its vicinity. The future explorer will find his field in the mountainous interiors and on the highest peaks.Note(April 19th, 1887).—Since I penned the above, further collections of reptiles and batrachians, made in these islands by Mr. C. M. Woodford, have been described by Mr. Boulenger at a recent meeting of the Zoological Society. I had the pleasure of meeting Mr. Woodford before he left England, and I hope that he has been able to accomplish his purpose of penetrating into the interior of one of the larger islands of the group.

Ina memoir on the Reptiles and Batrachians of the Solomon Islands, which was read before the Zoological Society, on May 6th, 1884,[439]Mr. Boulenger remarked that very little was known about the herpetology of these islands until two important collections, which I sent to the British Museum in 1883 and 1884, brought to light several new and interesting forms, such as could hardly have been expected from this region. “The position of this group of islands on the limits of two great zoological districts,”—this author proceeded to observe—“renders the study of its fauna of special interest, as it is the point where many of the Papuasian and Polynesian forms intermingle. Curiously, all the Batrachians belong to species not hitherto found elsewhere, and one of them is even so strongly modified as to be the type of a distinct family.”

[439]Published in the Transactions of the Society; vol. xii., part i., 1886. The diagnoses of most of the new species in my collections were given in the Proceedings for 1884: p. 210. Vide also “Annals and Magazine of Natural History” (5) xii., 1883.

According to Mr. Boulenger, the Reptiles may be grouped under four headings, viz.:—

1. Species belonging to both the Papuasian and Polynesian districts.

2. Indo-Malayan or Papuasian species, not extending further east or south-east.

3. Polynesian species, not extending further north and west than New Ireland.

4. Species not hitherto found elsewhere than in the Solomons (and New Ireland.)

1Gymnodactylus pelagicusGehyra oceanicaMabuia cyanuraPlaturus fasciatus.2Crocodilus porosusGecko vittatusVaranus indicusKeneuxia smaragdinaEnygrus carinatusDipsas irregularis.3Gonyocephalus godeffroyiMabuia carteretiiMa„uianigraEnygrus bibronii.4Lepidodactylus guppyi,n. sp.Lipinia anolis,n. sp.Corucia zebrataDendrophis solomonisHoplocephalus par,n. sp.

All of these 19 Reptiles were included in my collection, with the exception ofCorucia zebrata, which, however, came under my observation. I will now proceed to refer more particularly to the Reptile-fauna of this region.

Crocodiles.—The species of Crocodile (Crocodilus porosus, Schneid), which is so common in the Solomon Group, ranges from India and South China through the Malay Archipelago and Papuan Islands to North Australia. In these islands crocodiles appear to frequent in greatest numbers the swamps and sandy shores of uninhabited coral islands, such as those of the Three Sisters, and the coasts of the larger islands in the vicinity of the mouths of the streams and rivers. I frequently surprised them basking on the sand under the shade of a tree. On one occasion I was standing on the spreading roots of a tree that were exposed on the beach, when one of these reptiles darted out from under my feet and dived into the sea. Of the marks that they make on the sand when lying at rest, an oblong shallow impression corresponding to the head, and a curved well-defined grove caused by the tail are alone specially recognisable. When they are not alarmed and move leisurely along,they leave a double row of footprints on the sand, with a narrow median furrow produced by the weight of the tail; but when they have been disturbed and make a rush to escape, they raise their tail and leave only the tracks of their feet on the sand. These crocodiles are equally at home in salt and fresh water. I have frequently passed them in my Rob Roy canoe when they have been floating as though asleep at the surface of the sea; and it was always in the sea that they found a refuge when my little craft intruded itself within their haunts. They came under my notice in the fresh-water lakes of Santa Anna and Stirling Island, and in the lower courses of the streams in several localities. They are apparently in no uncongenial conditions in the salt-water lagoon of Eddystone Island, although its waters receive the hot sulphureous vapours of submerged fumaroles.

These crocodiles do not apparently attain a greater length than 12 or 13 feet. Mr. Sproul shot one at Santa Anna which measured 91⁄2feet. A female that I shot in the Shortland Islands, measured 11 feet. One of the seamen of the “Lark,” named Prior, obtained from the natives the skull of a rather larger specimen. Out of half-a-dozen individuals seen on the Three Sisters, not one measured more than 7 or 8 feet.[440]Mr. Bateman, a trader resident at Ugi, told me that at Wano on the St. Christoval coast he saw a very large crocodile which, from his description, appears to have been twice as long as any that I saw. It was, however, dusk at the time; and in connection with this circumstance I should add that I have found actual measurement to reduce the apparent length of a crocodile from 14 to 11 feet.

[440]A skull given to me by Mr. Nisbet, the government-agent of the “Redcoat,” at Ugi, was 12 inches long. It was obtained from the natives of Guadalcanar.

Natives are rarely attacked by these reptiles, and they show little or no fear of them. I have seen a full-grown crocodile dart under a line of swimmers without causing any dismay. Of the numbers I saw, all were but too anxious to get out of my way; and their cowardly nature is well shown in the account of my capture of a specimen which is given below. However, I came upon a man of Santa Anna who had had his leg broken by one of these reptiles. The natives of Rubiana hold the crocodile in veneration and work without fear in the places which it frequents. They believe that only faithless wives are seized and carried off by the monster. Pigs are occasionally the prey of the crocodile;but its usual diet appears to be opossums (Cusci), large lacertilians, and fish.

The following account of the capture of a crocodile may interest some of my readers. It was effected by no more formidable weapons than by a number of long staves and a small “bull-dog” revolver. Accompanied by six natives I was making the ascent of a large stream on the north-west side of Alu, when some of my companions espied a large crocodile at the bottom of a deep pool about 200 yards from the mouth of the stream. In setting to work to effect its capture my men proceeded very methodically to work, and evidently knew the tactics which the creature would employ. Standing in the water just below the pool, we stood awaiting the descent of the crocodile down the stream, whilst one of the natives was rousing it up with a long pole to make it leave its hiding-place. After a little time it began to get uneasy, and leaving the pool began to descend the stream. Where we were standing, the stream was only knee-deep, and as the reptile passed us in the shallow water some natives hit it on the head with their poles, whilst others hurled their poles sharpened at the ends, striking it in several places, and I planted a bullet behind its neck. The creature showed no fight and immediately hid itself in the pools near the mouth of the stream. During two hours, after we had been driving it from one pool to another by means of our pointed poles and staves, we seemed no nearer to its capture. At length there was a loud out-cry from the natives. The crocodile was making a final rush for life to cross the bar at the mouth of the stream and escape into the sea. We all followed, some in the canoe and some through the water; and for a short time I thought that the creature would escape. But being a little disabled by our previous attacks, its progress across the bar was somewhat checked; and the foremost of my men caught hold of its tail just as it was getting into deep water. Very quickly we all came up, and assisted in drawing it high and dry on the beach; and whilst two of our number kept hold of its tail, the remainder belaboured its neck with rocks and sticks until it died.[441]Its length proved to be 11 feet. Throughout the whole chase the reptile made no outcry, and even when we were belabouring it to death it only gave a kind of growl. In its stomach I found a large quantity of partially digested foodwith the remains of an opossum (Cuscus) and a large lizard 11⁄2feet long (probablyCorucia zebrata). It was a female, and, in the oviduct I came upon an egg, which my natives appropriated, saying that it was very good food; but they do not usually eat the flesh. I was unable from want of space to keep more than the head of the animal, which I cut off and carried back in my canoe to the ship. The skull is now in the British Museum.

[441]An illustration in Mr. Bates’ “Naturalist on the Amazons” represents a very similar scene.

Lizards.The Lacertilians are well represented in these islands. Those at present described are given in the subjoined list.

GeckonidæGymnodactylus pelagicusGehyra oceanicaLepidodactylus guppyi.n. sp.Gecko vittatusGe„kovar. bivittatus.AgamidæGonyocephalus godeffroyi.VaranidæVaranus indicus.ScincidæMabuia carteretiiMa„uiacyanuraMa„uianigraKeneuxia smaragdinaLipinia anolisn. sp.Corucia zebrata.

Geckonidæ

Agamidæ

Varanidæ

Scincidæ

The lizards, which most frequently meet the eyes of the visitors in the vicinity of the beaches, are the two skinks,Mabuia nigraandcyanura. As a rule those species that are common at the coast have a wide range, extending either into Polynesia or Papuasia or into both these regions (videpage 307). The species peculiar to these islands came less frequently under my observation. Thus, that ofLepidodactylus guppyi, is founded on a single (female) specimen I found in Faro or Fauro Island in Bougainville Straits.Corucia zebratanever came under my notice alive; it is said at Ugi to find its home in the foliage of the higher trees. Doubtless if I could havepenetrated to the higher regions of the large islands, I should have obtained a large number of new species. My collections refer for the most part to the sea-border and its vicinity. In the elevated interior of such an island as Guadalcanar there isa region of great promisefor the collector; but I shall have a further occasion to refer to this topic.

The Monitor,Varanus indicus, may be often seen at the coast, basking in the glare of the mid-day sun on the trunks of prostrate trees or on the bare rocks. It is considered edible by the natives of Bougainville Straits. Whilst we were anchored at Oima Atoll, Lieutenant Leeper captured a very large specimen (5 feet 73⁄4inches long)[442]on the rocks close to the sea, and towed it off alive to the ship. After we had tried in vain to strangle it by a cord, a lead was fastened to it and it was sunk overboard, but an hour passed before we could say that the reptile was really dead. This Monitor is probably able to swim considerable distances. It very likely owes its wide range (from Celebes to the Solomon Group including Cape York) to the agency of floating trees. On examining the stomach and intestines, I found them empty. An enormous quantity of fat, developed in two large lobes in connection with theomentumor some other part of theperitoneum, almost filled the abdominal cavity. With this store of sustenance and heat, these reptiles must be able to live without food for a long time.[443]

[442]A specimen shot in the Florida Islands measured 3 feet 8 inches.[443]As an instance of the tenacity of life that some reptiles possess, I may refer to the case of a young terrapin which I kept inadvertently for nearly five months on the coast of China without any sustenance except the dry rust of a tin can.

[442]A specimen shot in the Florida Islands measured 3 feet 8 inches.

[443]As an instance of the tenacity of life that some reptiles possess, I may refer to the case of a young terrapin which I kept inadvertently for nearly five months on the coast of China without any sustenance except the dry rust of a tin can.

Snakes.Hitherto, the following six species of Ophidians have been found in the Solomon Group. All of them were included in my collection and one of them has been described by Mr. Boulenger as a new species.

BoidæEnygrus carinatusEny„rusbibroniiColubridæDendrophis solomonisDipsas irregularisElapidæHoplocephalus parn. sp.Hydrophiidæ(Water-snakes)Platurus fasciatus[444]

Boidæ

Colubridæ

Elapidæ

Hydrophiidæ(Water-snakes)

[444]I was indebted to Lieutenant Symonds of H.M.S. “Diamond” for this snake.

One of the commonest of snakes throughout these islands isEnygrus carinatus, a harmless species of the Boa family. It often possesses considerable bulk in proportion to its length. One specimen which I obtained in Treasury Island measured 31⁄2feet in length and 6 inches in girth. I handled a good many living snakes whilst in these islands, since the natives used to bring them in numbers to me both on board and on shore. The statements of the natives and of the white men resident in this region and the general appearance of the snakes had led me to believe that there were no poisonous species in the group. I was therefore somewhat surprised when, on my arrival in England, I learned from Dr. Günther that I had found a new species as poisonous as the Cobra. On being shown the specimen by Mr Boulenger, I at once recognised an old friend which had been brought on board in a bamboo by the natives at Faro Island and had got loose on the deck. Whilst the men standing round were preparing to kill it with more regard for their own safety than for my feelings, I caught it quickly around the neck and held it under water until it was dead. The natives certainly were not aware of its venomous character, nor was Mr. Isabell, who was my right-hand man in these matters, and used to manage the ticklish progress of removing the snakes from their bamboo-tubes in a manner only suitable in the case of harmless species. I only obtained one specimen of this snake, which was about 21⁄2feet in length. It is namedHoplocephalus parand belongs to theElapidæ, a family of poisonous colubrine snakes which possess the physiognomy of the harmless snakes of the same sub-order, and include the Indian and African Cobras with other well known venomous species. In the footnote I have quoted Mr. Boulenger’s description of its general appearance for the information of those who visit the group.[445]

[445]The upper surface of the head is uniform blackish brown. The body is crossed above by broad red-brown bands separated by narrow white interspaces. The lower surface of the head and body are uniform white, except on the posterior extremity of the body where the red and black extend as lines along the sutures of the ventral shields. On the tail the red forms complete rings. Nearly every one of the dorsal scales have a blackish brown border. The head is depressed, moderately large, and slightly widened posteriorly. The eye has a vertical pupil.

Batrachians.—The Spanish discoverers in 1567 remarked that the natives of Isabel worshipped the toad (videpage 203), and one of the officers of Surville’s expedition in 1769, described in his journal a remarkable toad from the same island;[446]yet it is only within recent years that any Batrachians have been collected in this region. Before I arrived in the group only two species were known to science, and to this number my collections, which were made in the islands of Bougainville Straits, have added seven new species, including a type of a new family. The following list represents the Batrachian fauna of the Solomon Islands, as far as it is at present known:

[446]“Discoveries of the French in 1768 and 1769,” &c., by M. Fleurieu: London, 1791; p. 134.

Ranidæ.Rana buboniformis,n. sp.Rana guppyi,n. sp.Rana opisthodon,n. sp.Rana krefftii.Cornufer guppyi,n. sp.Cornufer solomonis,n. sp.Ceratobatrachidæ.(New family characterised by both jaws being toothed, and by the diapophyses of the sacral vertebra not being dilated.)Ceratobatrachus guentheri,n. sp.Hylidæ(Tree-frogs.)Hyla macrops,n. sp.Hyla thesaurensis.

Ranidæ.

Ceratobatrachidæ.

(New family characterised by both jaws being toothed, and by the diapophyses of the sacral vertebra not being dilated.)

Hylidæ(Tree-frogs.)

The natives of the islands of Bougainville Straits, where, as I have just remarked, my batrachian collection was chiefly made, have given frogs the general name of “appa-appa” in imitation of their noise, just as they have named the smaller lizards “Kurru-rupu” for the same reason. Amongst the particular species of frogs, I may refer to the large toad-likeRana buboniformis, which I found in Treasury Island, and on the highest peak of the island of Faro.Rana guppyi, according to Mr. Boulenger’s report, attains a larger size than anyother species of the genus, with the exception of the Bull-Frog of North America.Rana opisthodonaffords an instance of a Batrachian[447]which dispenses with the usual larval or tadpole stage, “the metamorphoses being hurried through within the egg.” On this subject I made the following notes. Whilst descending from one of the peaks of Faro Island, I stopped at a stream some 400 feet above the sea, where my native boys collected from the moist crevices of the rocks close to the water a number of transparent gelatinous balls rather smaller than a marble.[448]Each of these balls contained a young frog about 4 lines in length, apparently fully developed, with very long hind legs and short fore legs, no tail, and bearing on the sides of the body small tufts of what seemed to be branchiæ. On my rupturing the ball or egg in which the little animal was doubled up, the tiny frog took a marvellous leap into its existence and disappeared before I could catch it. When I reached the ship an hour after, I found that some of the eggs which had been carried in a tin had been ruptured on the way by the jolting, and the liberated frogs were leaping about with great activity. On placing some of them in an open bottle 8 inches high, I had to put the cover on as they kept leaping out. Mr. Boulenger remarking on this observation says, that there are no gills, but that on each side of the abdomen there are regular transverse folds (with an arrangement like that of the gill-openings of Plagiostomous Fishes), the function of which probably is that of breathing-organs. The tip of the snout is, he says, furnished with a small conical protuberance, projecting slightly through the delicate envelope of the egg, and evidently used to perforate that covering. In the instance also ofCornufer solomonis, another new species included in my collection, Mr. Boulenger remarks that there is every reason to believe that the young undergo the metamorphoses within the egg.

[447]Hylodes martinicensis affords another instance. Mon. Berl. Ac., 1876, p. 714.[448]According to Mr. Boulenger, they measure from 6 to 10 mm. in diameter.

[447]Hylodes martinicensis affords another instance. Mon. Berl. Ac., 1876, p. 714.

[448]According to Mr. Boulenger, they measure from 6 to 10 mm. in diameter.

With regard to the interesting species,Ceratobatrachus guentheri, which forms the type of a new family,Ceratobatrachidæ, the same writer observes that it is remarkable for the numerous appendages and symmetrical folds which ornate its skin. It is, in fact, “all points and angles,” and may be truly termed a horned frog. There is great variation both in the coloration and in the integuments. “Out of the twenty specimens before me,” thus Mr. Boulenger writes, “no two are perfectly alike.” The development is presumedto be of the type in which the metamorphoses are hurried through within the egg. These horned frogs are very numerous in the islands of Bougainville Straits, and so closely do they imitate their surroundings, both in colour and pattern, that on one occasion I captured a specimen by accidentally placing my hand upon it when clasping a tree.

It is particularly important to notice not only that the Batrachians of the Solomon Islands, as far as we at present know, do not occur elsewhere, but also that in this region a distinct family has been produced. These facts support the conclusions deducible from the geological evidence that these islands are of considerable geological age (videpage x.). The insular and isolated conditions have been preserved during a period sufficiently extended for the development of a peculiar Batrachian fauna.

The modes of dispersal of frogs and toads, and, in truth, of the whole Batrachian class, are matters of which we are to a great extent ignorant. Frogs are usually stated to be absent from oceanic islands, a peculiarity of distribution which apparently accords with the circumstance that neither they nor their spawn can sustain submersion in sea-water. The occurrence, however, of three species ofCornuferin the Caroline and Fiji Islands, and of a species ofBatoin the Sandwich Islands,[449]affects the general application of this conclusion. It may be suggested that these exceptions are due to human agency; but if so, it is difficult to understand why they have not been found in such a well explored island as New Caledonia.[450]

[449]Boulenger’s “Catalogue of the Batrachia Gradientia,” &c., 2nd edit., 1882.[450]Perhaps the peculiar geographical distribution of the Batrachia may throw light on this subject.Ibid.

[449]Boulenger’s “Catalogue of the Batrachia Gradientia,” &c., 2nd edit., 1882.

[450]Perhaps the peculiar geographical distribution of the Batrachia may throw light on this subject.Ibid.

In concluding this chapter I will refer to the circumstance that my collections of the Reptiles and Batrachians of this large group have only in a manner broken ground in a region which promises the richest results to the collector. It cannot be doubted that in the elevated interiors of the large islands, such as those of Bougainville and Guadalcanar, there will be found a peculiar Reptilian and Batrachian fauna, the study of which will be of the highest importance for the furtherance of our knowledge of these geologically ancient classes of animals. I believe I am correct in stating that it was on account of the highly interesting Batrachian collections I sent to the British Museum, that I received a grant for further exploration from the Royal Society, which, however, I was unfortunatelyprevented from turning to account. The work has yet to be done, and there can be little doubt that the man who is first able to examine the lofty interior of such an island as Guadalcanar will bring back collections, the importance of which will amply recompense him for any hardship or personal risk he may have endured. My experience was confined to the sea-border and its vicinity. The future explorer will find his field in the mountainous interiors and on the highest peaks.

Note(April 19th, 1887).—Since I penned the above, further collections of reptiles and batrachians, made in these islands by Mr. C. M. Woodford, have been described by Mr. Boulenger at a recent meeting of the Zoological Society. I had the pleasure of meeting Mr. Woodford before he left England, and I hope that he has been able to accomplish his purpose of penetrating into the interior of one of the larger islands of the group.

CHAPTER XV.GENERAL NATURAL HISTORY NOTES.Amongstthe numerous strange acquaintances which I made in the Solomon Islands, was that of the well known cocoa-nut crab, orBirgus latro; and I take this opportunity of giving my evidence towards the establishment of the fact of its cocoa-nut-eating propensity, for the following reason. When I read my notes on the subject before the Linnean Society of New South Wales on Dec. 27th, 1882,[451]I was surprised at the incredulity shown with reference to this extraordinary habit; and on inquiry, I learned that the evidence on the subject was deficient in one vital point, viz., the production of the writer who had witnessed this habit of the Robber Crab. Accordingly I referred to the various authors who have recorded this habit of theBirgus, and in no single account could I find that the writer had witnessed what he described. Neither Mr. Darwin, Dr. Seemann, Messrs. Tyerman and Bennet, Mr. T. H. Hood, the Rev. Wyatt Gill, nor the numerous authors whose accounts I also examined, seem to have actually witnessed theBirgusopening and eating a cocoa-nut. Herbst[452]was among the first to refer to this habit; whilst, long ago, M. M. Quoy and Gaimard[453]asserted, from their own observation, that the crab was fond of cocoa-nuts, and could be supported on them alone for many months, but they made no allusion to its capability of husking and opening them. The evidence on this point appears to have been always tendered by natives, excepting the account given to Mr. Darwin by Mr. Liesk, which is conclusive in itself.[454]Yet, credulous persons had fair grounds to retain their doubts, although in various works on natural history, popular and otherwise, this habit of theBirguswas described as an undoubted fact. I therefore submit my evidence; leaving to my reader toreply to the query—Can there be any reasonable doubt on the subject?[451]Proc. Lin. Soc. N.S.W.[452]Proc. Zool. Soc, 1832, p. 17.[453]Freycinet’s “Voyage autour du Monde,” 1817-20: Zoologie, p. 536. (Paris, 1824.)[454]“Journal of Researches,” p. 462.TheBirguswas to be found in most of the islands we visited. It is to be usually observed at or near the coast; but on one occasion, in St. Christoval, I found an individual at a height of 300 feet above the sea. Whilst traversing, in September, 1882, the belt of screw-pines, which borders the beach on the east coast of Malaupaina, the southern island of the Three Sisters, I came upon one of these large crabs, ensconced in the angle between the buttressed roots of a tree, with a full sized cocoa-nut within the reach of its pair of big claws. From the fresh-looking appearance of the shell, it had been evidently, but recently, husked, which operation had been performed more cleanly than if a native had done it. There was an opening at the eye-hole end of the shell of a somewhat regular oblong form, which measured 2 by 11⁄2inches, and was large enough to admit the powerful claws of the crab.[455]The white kernel, which had the firm consistence of that of the mature nut, had been scooped out to the extent of from 1 to 11⁄2inches around the aperture; small pieces of the kernel lay on the ground outside the nut, and others were floating about in the milk inside, of which the shell was about a fourth-part full.[455]This shell was presented to the Australian Museum, Sydney.I had, without a doubt, disturbed theBirgusin the middle of its meal; but, curiously enough, there were no cocoa-nut palms to be seen within fifty paces of the spot where the crab was found in its retreat. Not only had the shell been very recently husked, but it was evident, from the fresh condition of the milk and kernel, that an interval of less than a couple of hours had elapsed since the opening had been made. There was no possible explanation of the crab having got at the edible portion of the cocoa-nut, except through its own agency. The island is uninhabited, being only occasionally visited by fishing-parties of natives from St. Christoval, none of whom were on the island during the ship’s stay. There was, therefore, the strongest presumptive evidence that theBirgushad not only husked the cocoa-nut, but had also broken the hole at the end, in order to get at the kernel.I kept the crab alive on board on a diet of cocoa-nuts for three weeks, when, one morning, to my great disappointment, I found it dead. Other foods, such as bananas, were offered to it but were left untouched, and its appetite for cocoa-nuts continued unimpaired tothe last day of its life. Being desirous of observing the manner in which the husk was removed, I had a cocoa-nut with its husk placed in the coop in which the crab was kept. On one occasion theBirguswas surprised with the nut between its large claws; but, notwithstanding that no other food was offered to it for a day and a half, it did not attempt to strip off the husk. So the operation was done for it, and a small hole was knocked in the top of the shell. On the following day I found the shell—a young and somewhat thin one—broken irregularly across the middle, with the soft white kernel already removed and eaten. It was afterwards found necessary to break the nuts for its daily food.In 1884, when the “Lark” was in Bougainville Straits, three of these crabs were kept on board with the intention of taking them down to Sydney. Mr. W. Isabell, leading-stoker of the ship, looked well after them, as he had also done in the case of the previous crab, but within three or four weeks they had all died. The cocoa-nuts had to be husked and broken for them, as they were in vain tempted to do it for themselves. One crab, however, was frequently observed clasping between its claws a full-grown unhusked nut, the upper end of which showed deep grooves and dents from the blows of its claws; and Mr. Isabell and I came to the conclusion that the coop, in which these crabs were placed, was too low to allow of the free play of the great claws.My evidence alone would be sufficient to convict theBirgusof this offence: for an offender it would certainly be in the eyes of the owner of a plantation of cocoa-nut palms. I learned from Mr. Isabell that the first crab we had on board consumed, on the average, two cocoa-nuts in three days. A number of these crabs in a cocoa-nut plantation, might therefore prove a considerable pest: for, if this betokens the quantity of food which theBirgusconsumes in a state of nature, a single crab in the course of twelve months would dispose of about 250 cocoa-nuts, which represent the annual production of three palms and between 20 and 30 quarts of oil.As these crabs disliked observation, I was unable to gain much knowledge of their habits by watching. During the day-time they were sluggish, did not eat, and kept themselves in the further corner of the coop, as far from the light as possible. At night they moved about very actively and fed vigorously on the cocoa-nuts. The natives of the Shortlands, who were well-acquainted with the cocoa-nut eating habit of theBirgus, described to me the mode ofhusking and breaking the nut, just as Mr. Liesk described it to Mr. Darwin. They esteem as an especial luxury the fat which gives the chief bulk to the abdomen of the crab.The habit of theBirgus, when surprised away from its burrow, is not to turn round and run away, but to retreat in an orderly manner with its front to the foe. Having reached some root or trunk of a tree which protects in the rear its less perfectly armoured abdomen, it makes a regular stand, waves one of the long second pair of claws in the air, and courageously awaits the attack. The attitude of defence is worthy of remark. The two large claws are held up close together to defend the mouth and eyes, but with the pincers pointing downward—the posture reminding me of the guard for the head and face in sword-exercise. One of the long second pair of claws is planted firmly on the ground to give the crab additional support; whilst the other claw is raised in the air and moved up and down in a sparring fashion. The whole attitude of theBirgus, when on the defensive, is one of dogged and determined resistance. The big pincers that point downward are ready to seize anything which touches the unprotected under surface of the abdomen; but on account of the position of these claws in front of the eyes, it can only foresee attacks from above, and it therefore cannot ward off a sudden thrust directed against the abdomen, although it may afterwards inflict severe injuries on the aggressor.There seems to be some doubt whether theBirgusascends the tree to get the cocoa-nuts or whether it contents itself with those that have fallen. Almost every author who refers to this crab alludes to its climbing the tree, and it is also said to climb the pandanus. The testimony in support of its climbing powers is almost conclusive, yet Mr. Darwin was informed by Mr. Liesk that in Keeling Atoll theBirguslives only on the fallen cocoa-nuts, and Mr. H. O. Forbes,[456]who has recently visited this island, confirms this statement.[456]“A Naturalist’s Wanderings,” etc.: London, 1885, p. 27.My readers, after perusing the foregoing remarks, will agree with me that from the lack of actual observation on the part of the authors, who describe the cocoa-nut eating habit of this crab, there has been fair grounds for scepticism. Even now, we are but imperfectly acquainted with the mode of life of theBirgus, which is a subject I would commend to the attention of residents in the Indian and Pacific Oceans.I may add that theBirgusis partial to other kinds of fruits beside cocoa-nuts. Different writers mention candle-nuts, nutmegs, figs, and other rich and oily nuts and fruits. In some islands it would seem that the Pandanus fruit is its only diet; and for breaking open these tough fruits, its heavy claws are well adapted, though from personal experience, I should remark that the crab would have its strength and ingenuity taxed almost as much as in the case of the cocoa-nut.Ground-pigeon gizzardThe handsome ground-pigeon, known as the Nicobar pigeon (Geophilus nicobaricus), is commonly observed in the wooded islets on the coral reefs of the Solomon Group. As I have remarked onpage 293, this bird is probably instrumental in transporting from one locality to another the small hard seeds and fruits which the common fruit-pigeon (Carpophaga) refuses. That it is able to crack such hard seeds as those of the leguminous plantAdenanthera pavonina,[457]is shown by the fact that I have found these seeds cracked in the cavity of the gizzard, which is in its structure and mechanisma veritable pair of nutcrackers. In this bird the muscular stomach or gizzard is of a surprising thickness, and is provided with a very singular mechanical contrivance to assist its crushing power. As shown in the accompanyingdiagram, it is composed of two muscular halves, each having a maximum thickness of five-eighths of an inch and united with each other in front and behind by a stout distensible membrane, which is the proper wall of the organ. Developed in the horny epithelial lining membrane there are two cartilaginous bodies of hemispherical shape, one in each muscular segment of the gizzard, which measure about one-third of an inch in thickness andthree-fourths of an inch in diameter. The outer or convex surface of each cartilaginous body fits into a cup-shaped cavity which is lined by a semi-cartilaginous membrane, the whole constituting a “ball-and-socket” joint with well lubricated surfaces. The two surfaces of this pseudo-articulation are capable of easy movement on each other, being retained in close apposition by the attachment to the subjacent tissues of the horny epithelial lining membrane in which the cartilaginous body is developed. The inner or free surface of each hemispherical body, that which looks into the gizzard cavity, is somewhat concave, and projects a little above the surface of the lining membrane; it is much harder than the opposite convex side of the cartilage and has almost the consistence of bone, the arrangement of the cells into densely packed rows with but little intervening matrix indicating an approach towards ossification.[457]The Kuara tree of India, of whose hard seeds necklaces are made.The firm consistence of these hemispherical cartilages combined with the mechanism of a moveable articulation must greatly assist the already powerful muscular walls of the gizzard; but there is an additional factor in the crushing power in the constant presence of a small quartz pebble, usually about half-an-inch across. With such a apparatus, I can well conceive that very hard seeds and nuts may be broken, as in the case of the seeds ofAdenanthera pavoninaalready alluded to. The Nicobar pigeon is in fact possessed of a nut-cracking mechanism in its gizzard, by which nuts like those of our hazel tree would be cracked with comparative ease.With reference to the small quartz pebbles found in the gizzards of these birds, I should remark that there is usually only one present, and that it varies in weight between 30 and 60 grains. I was sometimes able to say where the pigeon had obtained its pebble. Thus, in Faro Island the bird often selects one of the bipyramidal quartz crystals, which occur in quantities in the beds of the streams in the northern part of the island, where they have been washed out of the quartz-porphyry of the district. In other instances the pebble seems to have been originally a small fragment of chalcedonic quartz, such as composes some of the flakes and worked flints that are found in the soil which has been disturbed for cultivation. Sometimes the pebble is of greasy quartz; and now and then in the absence of quartz the bird has chosen a pebble of some hard volcanic rock. It is a singular circumstance that although these pigeons frequent coral islets where they can easily find hard pebbles of coral-rock, they prefer the quartz pebbles whichare of comparatively rare occurrence. I never found any calcareous pebble in their gizzards, and was often at a loss to explain how the bird was able to ascertain for itself the different degree of hardness between the two pebbles, when the quartz was of the dull white variety. . . . I learn from a recent work on New Guinea by the missionaries, Messrs. Chalmers and Gill, that inside the gizzard of each Goura pigeon there is a good-sized pebble much prized by the natives as a charm against spear-thrusts and club blows.[458]The Goura pigeon resembles the Nicobar pigeon in habits; and I think it probable that its gizzard will be found to present a similar structure and mechanism for cracking nuts and hard seeds. The common fruit pigeons (Carpophaga) of the Solomon Islands, living as they do on soft fleshy fruits, and rejecting the hard seeds and kernels, have no peculiar structure of the gizzard, the walls of which are comparatively thin, and are thrown into permanent rugæ somewhat warty oh the surface.[458]“Work and Adventure in New Guinea” (p. 317): London, 1885.One of the most familiar birds in these islands is the “bush-hen,” which belongs to the family of the mound-builders (Megapodiidæ). They bury their eggs in the sand at a depth of between three and four feet. On one occasion in the island of Faro, Lieutenant Heming and his party found eight eggs, in different stages of hatching, thus buried: they were scattered about in the sand; and according to the account of the natives only one egg was laid by each bird. The eggs are sometimes found on the surface of the sand. The young birds are able to fly short distances soon after they are hatched. One that was brought on board astonished us all by flying some thirty or forty yards from the ship and then returning to the rigging.The account recently published by Mr. H. Pryer of his visit to the birds’ nest caves of Borneo[459]has opened up the discussion as to the nature of the substance of which the edible bird’s nest is composed. Many and varied have been the surmises as to the source of this material; but nearly all of them have been based on mere speculation, and have been relegated to the limbo of sea-tales. Amongst the earlier explanations, I may allude to those which have been given by early writers. The swiftlets (Collocalia), which build their nests in this extraordinary fashion, were considered to gather a gelatinous material from the ocean-foam, or from the bodies of holothurians, or from the skin of the sun-fish. The Chinese fishermenassured Kæmpfer that their nests were composed of the flesh of the great poulpe. A more probable explanation, however, was found by Rumphius in the occurrence on the sea-coasts of a soft almost cartilaginous plant which he with confidence asserted was the material from which these swiftlets constructed their nests; but subsequently this naturalist inclined to the opinion that the substance of which the edible birds’ nests are composed is merely a secretionary product. In these two views of Rumphius we have the two sides of the controversy very much as it at present stands. On the one hand, there are those who hold that this substance is a secretionary product: on the other hand, the opinion is held that the nest is constructed of a vegetable matter, usually resulting from the growth of a microscopic alga, which is found in the caves and on the faces of the cliffs where the nests occur. All the weight of experiment and of actual observation tends to negative the view of the vegetable origin of this substance. Sir Everard Home in 1817 declared his opinion that certain peculiar gastric glands, which he found in one of these birds, secreted the mucus of which the nest was formed. In 1859, Dr. Bernstein[460], after having carefully studied the habits of the birds in question, came to the conclusion that their nests are formed from the secretion of certain salivary glands which are abnormally developed during the nest-building season. M. Trécul, who held the same opinion, showed that the bird constructs its nest by means of a mucus which flows abundantly from its beak at the pairing time.[461]This last view is strongly supported by Mr. Layard, who unhesitatingly pronounces his opinion that these swiftlets build their nests from the secretionary products of their own salivary glands.[462]However, when Mr. Pryer visited in March, 1884, the birds’ nest caves in British North Borneo, he considered that he had found the source of the material of which the nests were composed in the occurrence of a “fungoid growth,” which incrusted the rock in damp places, and which, when fresh, resembled half-melted gum tragacanth. Without at present expressing an opinion as to the validity of the inference Mr. Pryer drew from his observations in these caves, I may observe that the “fungoid growth” has been determined by Mr. George Murray,[463]of the Botanical Department of the British Museum, to be the result of the growthof a microscopic alga, a species, probably new, ofGlœocapsa; whilst the edible nests from these caves, according to a chemical and microscopical examination made by Mr. J. R. Green,[464]have been shown to be formed in the great mass ofmucin, which is the chief constituent of the mucous secretions of animals. After examining various specimens of edible nests from other localities, Mr. Green subsequently confirmed the results of his first experiments. The nest-substance, as he unhesitatingly states, is composed ofmucin, or of a body closely related to it.[465]So far, therefore, there would appear to be but little evidence to support the view of Mr. Pryer that the species of alga, which he found incrusting the rock in the vicinity of the Borneo caves, supplied the material for the construction of the nests of the swiftlets. However, before proceeding to state my own opinion on the matter, I will refer briefly to my observations in the Solomon Islands relating to this question.[459]Proceedings of the Zoological Society for 1884: p. 532.[460]Journ. für Ornithologie, 1859, pp. 112-115; also Proceed. Zoolog. Soc., 1885, p. 610.[461]“A General System of Botany,” by Le Maout and Decaisne: London, 1873, p. 983.[462]“Nature,” Nov. 27th, 1884.[463]Proc. Zoolog. Soc., 1884: p. 532.[464]Proc. Zool. Soc., 1884, p. 532.[465]“Nature,” Dec. 11th, 1884 and May 27th, 1886.A species ofCollocalia, which usually frequents inaccessible sea-caves and cliffs, is frequently to be observed on the coasts of the islands of this group. The natives of Treasury Island call this bird “kin-kin;” but they have no knowledge of the nutrient qualities of the substance of which it builds its nest, and they were much amused when I told them of its being a Chinese luxury. I only came upon the nests of this bird on one occasion, and that was in some caves on Oima Atoll in Bougainville Straits. A description of these caves will be here unnecessary. As in the instance of the birds of the Borneo caverns, these swiftlets shared their retreats with a number of large bats, the accumulation of whose droppings had produced a thick reddish-brown deposit on the floors of the caves. The nests, which were formed for the most part of fibres derived evidently from the vegetable drift[466]at the mouths of the caves, were thickly incrusted with the gelatinous incrustation which projected as winglets from the sides and fastened them to the rock.[466]The husks of pandanus seeds more particularly.A reddish soft gelatinous incrustation occurred on the faces of some of the cliffs in the vicinity of the caves. It was composed of an aggregation of the cells of a microscopic unicellular alga which measure1⁄2500of an inch in diameter. Unfortunately the specimens of this growth which I collected have been mislaid, but there can be little doubt that it is similar to the “fungoid growth” which Mr.Pryer describes in connection with the Borneo caves, and which, through the kindness of Mr. George Murray, I had the opportunity of seeing at the British Museum. On the faces of the coral limestone cliffs of some islands, such as on the east coast of Santa Anna, a like growth occurs in considerable quantity. In its freshest condition, it may be described as a reddish-yellow, gum-like substance forming a layer1⁄4to1⁄8of an inch in thickness. Where it incrusts the overhanging face of a cliff, it is more fluid in consistence and sometimes hangs in little pendulous masses, one to two inches in length, the extremities of which are often distended with water. This alga decomposes the hard coral limestone, making the surface of the rock soft and powdery. All stages in the growth of this substance may be observed. The older portions are very dark in colour and have a tough consistence; and in the final stage it occurs as a black powder covering the rock surface. On examining this alga with the microscope, I found it to be formed almost entirely of granular matter apparently resulting from the death of the cells; whilst the presence of a few cellular bodies alone gave me an indication of its true nature.From my observations relating to the subject of the edible bird’s nest, it may be therefore inferred that in the Solomon Islands, as in Borneo, the occurrence of these nests is associated with the presence of a protophytic alga, which incrusts the rocks of the locality as a gelatinous or gum-like substance. Whether or not the birds employ this material in forming their nests, is a question which would appear to have been already answered in the negative; but it seems to me that those who hold that this material is used for this purpose might justly claim that the final judgment should be suspended, until a chemical examination of this vegetable substance has been made with the object of determining whether it might not yield a material closely resemblingmucin. Amongst the nitrogenous constituents of plants occurs the so-calledvegetable albumen, which in its chemical composition and in its behaviour with re-agents does not differ materially from theblood-albumenof the animal organism, of which in fact it is the source. In suggesting, therefore, that avegetable mucinmay be found in this low plant-growth, I do not pass beyond the bounds of probability.[467][467]Videa letter by the writer in “Nature,” June 3rd, 1886.Small scorpions came under my notice in Faro Island. They are not usually more than 11⁄2in length and occur in narrow clefts ofrocks and in the crevices of trees. I was stung by one on the thumb, but the pain was trifling and soon passed away.[468][468]Specimens of these scorpions were given by me to the Australian Museum, Sydney.A species ofIulusor Millipede, which attains a length of from 6 to 7 inches, is commonly found in the eastern islands of the Solomon Group on the trunks of fallen trees and amongst decaying vegetable débris. It is often to be seen amongst the rotting leaves that have gathered inside the bases of the fronds of the Bird’s-nest Fern (Asplenium nidus). These Myriapods seem to be less frequent in the islands of Bougainville Straits towards the opposite end of the group, as I do not remember seeing any largeIuliin that locality: their place appears to be taken by another Myriapod, apparently aPolydesmus, growing to a length of 21⁄2inches, which I found amongst decaying vegetation at all elevations up to 1900 feet above the sea, as on the summit of Faro Island. But to return to theIuli, I should remark that this genus of Myriapods evidently possesses some means of transportal across wide tracts of sea, since, amongst other islands similarly situated, it is found in Tristan da Cunha,[469]in the South Atlantic Ocean, and I have found it in the Seychelles, in the Indian Ocean. The habits of these Millipedes would render it highly probable that they have reached the oceanic islands on vegetable drift, such as floating logs. It is, however, a noteworthy circumstance that they do not seem to be able to withstand immersion in sea-water for any length of time. In experimenting on the Solomon Island species, I found that they were able to survive an hour-and-a-half’s complete immersion in sea-water, but that an immersion of three hours killed them. One individual, out of several experimented on, survived for twelve hours after it was taken out, but only in a half lifeless condition.[470]It may, therefore, have been that theIulushas been transported to oceanic islands by such agencies as canoes and ships, rather than by means of floating trees.[471][469]Moseley’s “Naturalist on the Challenger,” p. 134.[470]This species ofIuluswas able to sustain a longer submersion in fresh-water, without apparently any injurious effects. Those experimented on recovered after being kept under water for four hours, but died after a submersion of six hours.[471]As bearing on this point, it might be interesting to determine whether these largeIulioccur on islands far from land which are believed never to have been inhabited.Like other species of the genus, the Solomon IslandIulusexhales a very pungent and disagreeable odour, which is caused by an acrid fluid secreted by small vesicles, of which each segment of thebody contains a pair.[472]On holding my nose for a moment over the mouth of a bottle, containing two of these large Millipedes, I experienced a strong sensation in the nasal passages, reminding me much of the effects of an inhalation of chlorine gas. I had previously learned from resident traders that these Millipedes have a habit of ejecting an acrid fluid when disturbed, which, if it entered the eye, was liable to cause acute inflammation; and the instance was related to me of the captain of some ship, trading in these islands, who lost the sight of one of his eyes from this cause. Mr. C. F. Wood learned from the natives of St. Christoval, in 1873, that these Myriapods “could squirt out a poisonous juice, which was dangerous if it happened to touch one’s eye;” but he adds, “there seemed no great probability of their doing this.”[473]However, I usually found that native testimony, in such matters, was very reliable; and in the instance of this reputed habit of theIulus, my personal experience has convinced me of its reality. Whilst handling one of these Millipedes as it lay on the trunk of a fallen tree in Ugi Island, I felt a sudden smarting sensation in the right eye, caused apparently by some fluid ejected into it. Remembering the injurious effect attributed to this habit of theIulus, I at once plunged my head under the water of a stream, in which I happened to be standing up to my waist, and I kept my eye open to wash away the offending fluid. During the remainder of the day, there was an uncomfortable feeling in the eye and somewhat increased lachrymation; but on the following morning these effects had disappeared. At the time of this occurrence, my face was removed about a foot from the Millipede; and, although I was uncertain from what part of the body the fluid was ejected, I did not care, under the circumstances, to continue the inquiry.[472]Hoeven’s Zoology. (Eng. edit.) Vol. I., p. 291.[473]“A Yachting Cruise in the South Seas,” p. 131. (London, 1875.)Amongst the first living creatures to greet the visitor as he lands on the beach of a coral island in the Pacific, is a small species of Hermit-Crab, belonging to the genusCoenobita, which frequents the beach in great numbers. The crab withdraws itself just within the mouth of the shell, where it forms a perfect operculum, by means mainly of the large flattenedchelæof the left great claw which is arched over by the left leg of the third pair, whilst the right claw and the right leg of the second pair serve to complete the shieldThe most plucky and pugnacious of these little crabs are those which occupy cast-offNeritashells, a character which probably arises from their consciousness of the solid strength of the home they have chosen: and, strange to say, the tiny bosses on the surfaces of the large pincers, which are outermost in the improvised operculum, resemble similar markings on the outer side of the operculum of theNerita(N. marmorata, Hombr and Jacq), whose shell they often inhabit. Mr. Darwin[474]observed that the different species of hermit-crabs, which he found on the Keeling Islands in the Indian Ocean, used always certain kind of shells; but I could not satisfy myself that such was the case in the instance of the Solomon Island hermit-crabs. In the case of the common beach species ofCoenobita, I found, after carefully examining a number of individuals to satisfy myself of their being of the same species, that shells of the generaTurbo,Nerita,Strombus,Natica,Distorsio, Truncatella,Terebra,Melania, &c., &c., contained the same species ofCoenobita, whether the individual was large enough to occupy aTurboshell of the size of a walnut or sufficiently small to select the tiny shell of theTruncatellafor its home. Another species of the same genus prefers usually the vicinity of the beach; but it may occur at heights up to 200 feet above the sea. It is rather larger than the beach species, and differs amongst other characters in the more globose form of the large claws and in the greater relative size of the left one. It occupies shells of different kinds, such as those ofNerita,Turbo, &c. A still larger species, which frequents the vicinity of the beach, usually selectsTurboshells, apparently because of their larger size. All the other species ofCoenobita, which I met with, used, when I touched them, to withdraw themselves within their shells and close them up at once with their claws; but this kind, when I caught hold of theTurboshell that it carried, left the shell behind in my fingers with apparent unconcern and crawled leisurely away, displaying, somewhat indecorously, the rudimentary plates on the back of its abdomen. These are the plates that attain their greatest development in the Cocoa-nut Crab (Birgus latro), which is thus able to dispense with a shell altogether. The greatest heights at which I found hermit-crabs were in the island of Faro on the two highest peaks, which are elevated respectively 1600 and 1900 feet above the sea. In both these localities, the crab had reached the very summit and could not have climbed higher. Thespecies was apparently different from, though closely allied to, the common beach species, and frequented the shells of a land-snail (Helix). I was indebted to Lieutenant Heming for directing my attention to the hermit-crab, found 1900 feet above the sea. It appears to me likely that these hermit-crabs will be found at much greater heights in this group, since, in this island, their ambition to rise had carried them up as far as they could go.[474]“Journal of the Beagle,” p. 457.Other species of hermit-crabs, that are common in these islands, belong to the genusPagurus. They are conspicuously distinguished from the species ofCoenobita, above described, by their first pair of claws, which are small and weak and ill-adapted for defensive purposes. For this reason, these species are less able to look after themselves; and since they cannot form the operculum-like shield with their claws at the mouth of the shell, they always choose shells which will permit of their retiring well within it, so as to be out of the reach of their enemies. Some species are found in the stream-courses and in the brackish water near their mouths, when they often frequent cast-offMelaniashells. Other species (?) prefer the sea-water on the reef-flats. I noticed one individual that displayed its eccentricity of disposition, in selecting, as its abode, the hollow tube of a small water-logged stick, about six inches long, which it dragged about after it during its peregrinations, and into which it retreated when alarmed. On one occasion, I observed a largeDoliumshell, moving briskly about in a pool of salt-water, which, on picking up, I found to be tenanted by aPagurus, so ridiculously small, in comparison with the size of the shell, that when frightened it retreated to the very uppermost whorl, and, notwithstanding the wide mouth of the shell, could not be seen. So light was the weight of the crab, that, on account of the buoyancy of its shell, it floated lightly on the surface of the water, on which I had placed it with the mouth of the shell uppermost, and was blown by a slight breeze across a pool of water, some twenty yards in width. While it was afloat, the shrewd little occupant retired to the innermost recess of its home; but as soon as the shell had grounded, it protruded its head and pincers and endeavoured to overturn the shell, which it finally succeeded in accomplishing.In the case of these two genera of hermit-crabs,CoenobitaandPagurus, it was interesting to notice the relation existing between the defensive capabilities of the crab, and the relative size of the shell it selected as its home. ThePagurus, with its weak slenderpincers, chooses large shells within which it can retire well out of reach when alarmed. TheCoenobita, with its stout pincers, prefers shells much smaller, relatively speaking, and ensconces itself snugly in the body whorl, forming an operculum with its claws. As the hermit-crab,Coenobita, crawls along the dry sand of a beach, it leaves behind it characteristic pinnate tracks which may be often traced for several feet. The lateral markings are produced by the claws and legs working on each side of the shell; whilst a central groove is formed by the weight of the shell itself. As shown by the arrow in thediagram, the lateral markings point in the direction of the course which the hermit-crab has taken. Sometimes only a single row of lateral tracks accompanies the grooves produced by the shell. Such markings were produced by a hermit-crab when frightened by my approach. It turned its front towards me, and crawled backwards, by working most of his claws and legs on one side of the shell. In the case of the larger hermit-crabs, which are much less frequent on the beach, each limb produces a distinct print on the sand; but with the small species ofCoenobitawhich infests the beach, each lateral marking, as shown in the diagram, is produced by a single movement of the claws situated on the same side of the shell. The hermit-crabs only leave their tracks on the dry loose sand. One individual, that I placed on sand, still wet from the retreating tide, crawled along without leaving any impression. I have described these impressions with some care, as they bear on the origin of the surface-markings of rocks of shallow-water formation, a subject recently discussed in the geological world. It is highly probable that some of the larger and heavier forms of the Anomura (and, in fact, of the Decapoda generally) would produce prints such as I have here described, both on mud-flats left dry by the tide, and on the soft bottom in shallow depths. A cast of the impressions thus produced would have an unmistakeable plant-like form.Track of hermit crabWhilst examining the island of Simbo, I noticed some singular Medusæ in a small mangrove-swamp, which is inclosed in the low point that forms the south shore of the anchorage. Numbers of these organisms of a large size (8 or 9 inches across the umbrella), and of a dirty-white colour, were lying on the mud with theirtentacles, uppermost in depths of from one to three feet of water. I was struck by the handsome mass of arborescent tentacles which they displayed, and by the peculiarity of their lying upside-down. The dark mud which formed the bottom of the swamp was composed of decayed vegetable matter, confervoid growths, diatoms, and a few infusoria: but when I raised up these Medusæ, I found underneath each a patch of white sand corresponding with the outline of the organism, but completely concealed by the umbrella when the Medusa lay in its usual position. The sand was derived from corals, shells, and the volcanic rocks of the island; and the light patches formed a marked contrast with the dark mud around. I was unable to find any satisfactory explanation of these curious patches of sand; and I, therefore, proceeded to interrogate the Medusæ on the subject by watching them, but to no purpose. So I had my revenge by turning them all over on their tentacles, when each one immediately began to contract its umbrella in a most methodical fashion, and, after swimming a short distance, deliberately resumed its former position of tentacles upward. I had an extensive experience of mangrove-swamps after we left Simbo; but these self-willed Medusæ never came under my notice again.[475][475]I referred to the habits of these Medusæ in “Nature,” Nov. 9th, 1882.With regard to these Medusæ, I should remark that they belong to a species ofPolyclonia, and are classed amongst the Scypho-Medusæ.[476]Two species ofPolycloniaseem to be known,P. frondosa(Agassiz) andP. Mertensii(Brandt), the first found in the Florida seas, and the latter in the Carolines. I am inclined to think that the Solomon Island species is more nearly allied toP. Mertensii. Both species, however, have similar habits, lying on the mud of mangrove-swamps, with their tentacles uppermost.[476]I compared my notes with the description and figures given by Agassiz in his “Contrib. Nat. Hist. U.S.A.” (1862: vols. iii. and iv.). In the Solomon Island species, the dendriform mass resolves itself into 8 principal branches, each ramose, and all united at their bases by a common membrane. The umbrella, which was finely lobed or crenulated at its margin, displayed about 40 radiating canals, each communicating by an anastomosing network with the canal on either side of it.The singular habits of these Scypho-Medusæ were noticed by Brandt in 1838. They have since been remarked by Mosely[477]in the Philippines, and by Archer[478]in the West Indies. L. Agassiz in his “Contributions to the Natural History of the United States,” describes and figures the Florida species (Polyclonia frondosa); andsome additional notes on its habits have been made by A. Agassiz, to whose communication in “Nature” (Sept. 29th, 1881) I have been much indebted.[477]Mosely’s “Notes by a Naturalist,” p. 404.[478]“Nature” Aug. 4th, 1881.Whilst we lay at anchor in Treasury Harbour, in April, 1884, a cetacean, unknown to the natives and to ourselves, got partly stranded in the shallow water, and was captured by the villagers. It was nine feet long, and possessed this remarkable character that, although no teeth showed through the gums, each lower jaw possessed a short, conical, hollow tooth an inch long, placed at the anterior extremity. I obtained the head from the natives, and placed it in a safe place, as I thought; but when we returned to Treasury a few weeks after, I found only portions of the skull with the lower jaw-bones, the wild pigs having held a feast over it. The remains, however, together with my notes and a sketch by Lieutenant Leeper were sent to the British Museum. I there learned that it is a species of Ziphius, probably unknown.The Solomon Islanders believe in the existence of anthropoid apes in the interiors of the large islands, regarding them, however, like the Dyaks of Borneo in the case of the Orang-utan, as “wild men of the woods.” In Malaita they are said to be 41⁄2to 5 feet high, and to come down in troops to make raids on the banana plantations. Captain Macdonald informed me that the natives allege that one of these apes was caught, and, after being kept for some time, escaped. Taki, the St. Christoval chief, told Mr. Stephens that he had seen one of these apes, and pointed out the locality. Tanowaio, the Ugi chief, also made a similar statement. In Guadalcanar, they are believed to live in the trees, and to attack men. Dr. Codrington refers to the prevalence of these beliefs throughout Melanesia (Journ. Anthrop. Inst., vol. x. p. 261). Such beliefs, as experience has shown in the case of the Gorilla and other anthropoids, have undoubtedly some foundation; but whether these mysterious animals are apes is quite another question.

Amongstthe numerous strange acquaintances which I made in the Solomon Islands, was that of the well known cocoa-nut crab, orBirgus latro; and I take this opportunity of giving my evidence towards the establishment of the fact of its cocoa-nut-eating propensity, for the following reason. When I read my notes on the subject before the Linnean Society of New South Wales on Dec. 27th, 1882,[451]I was surprised at the incredulity shown with reference to this extraordinary habit; and on inquiry, I learned that the evidence on the subject was deficient in one vital point, viz., the production of the writer who had witnessed this habit of the Robber Crab. Accordingly I referred to the various authors who have recorded this habit of theBirgus, and in no single account could I find that the writer had witnessed what he described. Neither Mr. Darwin, Dr. Seemann, Messrs. Tyerman and Bennet, Mr. T. H. Hood, the Rev. Wyatt Gill, nor the numerous authors whose accounts I also examined, seem to have actually witnessed theBirgusopening and eating a cocoa-nut. Herbst[452]was among the first to refer to this habit; whilst, long ago, M. M. Quoy and Gaimard[453]asserted, from their own observation, that the crab was fond of cocoa-nuts, and could be supported on them alone for many months, but they made no allusion to its capability of husking and opening them. The evidence on this point appears to have been always tendered by natives, excepting the account given to Mr. Darwin by Mr. Liesk, which is conclusive in itself.[454]Yet, credulous persons had fair grounds to retain their doubts, although in various works on natural history, popular and otherwise, this habit of theBirguswas described as an undoubted fact. I therefore submit my evidence; leaving to my reader toreply to the query—Can there be any reasonable doubt on the subject?

[451]Proc. Lin. Soc. N.S.W.[452]Proc. Zool. Soc, 1832, p. 17.[453]Freycinet’s “Voyage autour du Monde,” 1817-20: Zoologie, p. 536. (Paris, 1824.)[454]“Journal of Researches,” p. 462.

[451]Proc. Lin. Soc. N.S.W.

[452]Proc. Zool. Soc, 1832, p. 17.

[453]Freycinet’s “Voyage autour du Monde,” 1817-20: Zoologie, p. 536. (Paris, 1824.)

[454]“Journal of Researches,” p. 462.

TheBirguswas to be found in most of the islands we visited. It is to be usually observed at or near the coast; but on one occasion, in St. Christoval, I found an individual at a height of 300 feet above the sea. Whilst traversing, in September, 1882, the belt of screw-pines, which borders the beach on the east coast of Malaupaina, the southern island of the Three Sisters, I came upon one of these large crabs, ensconced in the angle between the buttressed roots of a tree, with a full sized cocoa-nut within the reach of its pair of big claws. From the fresh-looking appearance of the shell, it had been evidently, but recently, husked, which operation had been performed more cleanly than if a native had done it. There was an opening at the eye-hole end of the shell of a somewhat regular oblong form, which measured 2 by 11⁄2inches, and was large enough to admit the powerful claws of the crab.[455]The white kernel, which had the firm consistence of that of the mature nut, had been scooped out to the extent of from 1 to 11⁄2inches around the aperture; small pieces of the kernel lay on the ground outside the nut, and others were floating about in the milk inside, of which the shell was about a fourth-part full.

[455]This shell was presented to the Australian Museum, Sydney.

I had, without a doubt, disturbed theBirgusin the middle of its meal; but, curiously enough, there were no cocoa-nut palms to be seen within fifty paces of the spot where the crab was found in its retreat. Not only had the shell been very recently husked, but it was evident, from the fresh condition of the milk and kernel, that an interval of less than a couple of hours had elapsed since the opening had been made. There was no possible explanation of the crab having got at the edible portion of the cocoa-nut, except through its own agency. The island is uninhabited, being only occasionally visited by fishing-parties of natives from St. Christoval, none of whom were on the island during the ship’s stay. There was, therefore, the strongest presumptive evidence that theBirgushad not only husked the cocoa-nut, but had also broken the hole at the end, in order to get at the kernel.

I kept the crab alive on board on a diet of cocoa-nuts for three weeks, when, one morning, to my great disappointment, I found it dead. Other foods, such as bananas, were offered to it but were left untouched, and its appetite for cocoa-nuts continued unimpaired tothe last day of its life. Being desirous of observing the manner in which the husk was removed, I had a cocoa-nut with its husk placed in the coop in which the crab was kept. On one occasion theBirguswas surprised with the nut between its large claws; but, notwithstanding that no other food was offered to it for a day and a half, it did not attempt to strip off the husk. So the operation was done for it, and a small hole was knocked in the top of the shell. On the following day I found the shell—a young and somewhat thin one—broken irregularly across the middle, with the soft white kernel already removed and eaten. It was afterwards found necessary to break the nuts for its daily food.

In 1884, when the “Lark” was in Bougainville Straits, three of these crabs were kept on board with the intention of taking them down to Sydney. Mr. W. Isabell, leading-stoker of the ship, looked well after them, as he had also done in the case of the previous crab, but within three or four weeks they had all died. The cocoa-nuts had to be husked and broken for them, as they were in vain tempted to do it for themselves. One crab, however, was frequently observed clasping between its claws a full-grown unhusked nut, the upper end of which showed deep grooves and dents from the blows of its claws; and Mr. Isabell and I came to the conclusion that the coop, in which these crabs were placed, was too low to allow of the free play of the great claws.

My evidence alone would be sufficient to convict theBirgusof this offence: for an offender it would certainly be in the eyes of the owner of a plantation of cocoa-nut palms. I learned from Mr. Isabell that the first crab we had on board consumed, on the average, two cocoa-nuts in three days. A number of these crabs in a cocoa-nut plantation, might therefore prove a considerable pest: for, if this betokens the quantity of food which theBirgusconsumes in a state of nature, a single crab in the course of twelve months would dispose of about 250 cocoa-nuts, which represent the annual production of three palms and between 20 and 30 quarts of oil.

As these crabs disliked observation, I was unable to gain much knowledge of their habits by watching. During the day-time they were sluggish, did not eat, and kept themselves in the further corner of the coop, as far from the light as possible. At night they moved about very actively and fed vigorously on the cocoa-nuts. The natives of the Shortlands, who were well-acquainted with the cocoa-nut eating habit of theBirgus, described to me the mode ofhusking and breaking the nut, just as Mr. Liesk described it to Mr. Darwin. They esteem as an especial luxury the fat which gives the chief bulk to the abdomen of the crab.

The habit of theBirgus, when surprised away from its burrow, is not to turn round and run away, but to retreat in an orderly manner with its front to the foe. Having reached some root or trunk of a tree which protects in the rear its less perfectly armoured abdomen, it makes a regular stand, waves one of the long second pair of claws in the air, and courageously awaits the attack. The attitude of defence is worthy of remark. The two large claws are held up close together to defend the mouth and eyes, but with the pincers pointing downward—the posture reminding me of the guard for the head and face in sword-exercise. One of the long second pair of claws is planted firmly on the ground to give the crab additional support; whilst the other claw is raised in the air and moved up and down in a sparring fashion. The whole attitude of theBirgus, when on the defensive, is one of dogged and determined resistance. The big pincers that point downward are ready to seize anything which touches the unprotected under surface of the abdomen; but on account of the position of these claws in front of the eyes, it can only foresee attacks from above, and it therefore cannot ward off a sudden thrust directed against the abdomen, although it may afterwards inflict severe injuries on the aggressor.

There seems to be some doubt whether theBirgusascends the tree to get the cocoa-nuts or whether it contents itself with those that have fallen. Almost every author who refers to this crab alludes to its climbing the tree, and it is also said to climb the pandanus. The testimony in support of its climbing powers is almost conclusive, yet Mr. Darwin was informed by Mr. Liesk that in Keeling Atoll theBirguslives only on the fallen cocoa-nuts, and Mr. H. O. Forbes,[456]who has recently visited this island, confirms this statement.

[456]“A Naturalist’s Wanderings,” etc.: London, 1885, p. 27.

My readers, after perusing the foregoing remarks, will agree with me that from the lack of actual observation on the part of the authors, who describe the cocoa-nut eating habit of this crab, there has been fair grounds for scepticism. Even now, we are but imperfectly acquainted with the mode of life of theBirgus, which is a subject I would commend to the attention of residents in the Indian and Pacific Oceans.

I may add that theBirgusis partial to other kinds of fruits beside cocoa-nuts. Different writers mention candle-nuts, nutmegs, figs, and other rich and oily nuts and fruits. In some islands it would seem that the Pandanus fruit is its only diet; and for breaking open these tough fruits, its heavy claws are well adapted, though from personal experience, I should remark that the crab would have its strength and ingenuity taxed almost as much as in the case of the cocoa-nut.

Ground-pigeon gizzard

The handsome ground-pigeon, known as the Nicobar pigeon (Geophilus nicobaricus), is commonly observed in the wooded islets on the coral reefs of the Solomon Group. As I have remarked onpage 293, this bird is probably instrumental in transporting from one locality to another the small hard seeds and fruits which the common fruit-pigeon (Carpophaga) refuses. That it is able to crack such hard seeds as those of the leguminous plantAdenanthera pavonina,[457]is shown by the fact that I have found these seeds cracked in the cavity of the gizzard, which is in its structure and mechanisma veritable pair of nutcrackers. In this bird the muscular stomach or gizzard is of a surprising thickness, and is provided with a very singular mechanical contrivance to assist its crushing power. As shown in the accompanyingdiagram, it is composed of two muscular halves, each having a maximum thickness of five-eighths of an inch and united with each other in front and behind by a stout distensible membrane, which is the proper wall of the organ. Developed in the horny epithelial lining membrane there are two cartilaginous bodies of hemispherical shape, one in each muscular segment of the gizzard, which measure about one-third of an inch in thickness andthree-fourths of an inch in diameter. The outer or convex surface of each cartilaginous body fits into a cup-shaped cavity which is lined by a semi-cartilaginous membrane, the whole constituting a “ball-and-socket” joint with well lubricated surfaces. The two surfaces of this pseudo-articulation are capable of easy movement on each other, being retained in close apposition by the attachment to the subjacent tissues of the horny epithelial lining membrane in which the cartilaginous body is developed. The inner or free surface of each hemispherical body, that which looks into the gizzard cavity, is somewhat concave, and projects a little above the surface of the lining membrane; it is much harder than the opposite convex side of the cartilage and has almost the consistence of bone, the arrangement of the cells into densely packed rows with but little intervening matrix indicating an approach towards ossification.

[457]The Kuara tree of India, of whose hard seeds necklaces are made.

The firm consistence of these hemispherical cartilages combined with the mechanism of a moveable articulation must greatly assist the already powerful muscular walls of the gizzard; but there is an additional factor in the crushing power in the constant presence of a small quartz pebble, usually about half-an-inch across. With such a apparatus, I can well conceive that very hard seeds and nuts may be broken, as in the case of the seeds ofAdenanthera pavoninaalready alluded to. The Nicobar pigeon is in fact possessed of a nut-cracking mechanism in its gizzard, by which nuts like those of our hazel tree would be cracked with comparative ease.

With reference to the small quartz pebbles found in the gizzards of these birds, I should remark that there is usually only one present, and that it varies in weight between 30 and 60 grains. I was sometimes able to say where the pigeon had obtained its pebble. Thus, in Faro Island the bird often selects one of the bipyramidal quartz crystals, which occur in quantities in the beds of the streams in the northern part of the island, where they have been washed out of the quartz-porphyry of the district. In other instances the pebble seems to have been originally a small fragment of chalcedonic quartz, such as composes some of the flakes and worked flints that are found in the soil which has been disturbed for cultivation. Sometimes the pebble is of greasy quartz; and now and then in the absence of quartz the bird has chosen a pebble of some hard volcanic rock. It is a singular circumstance that although these pigeons frequent coral islets where they can easily find hard pebbles of coral-rock, they prefer the quartz pebbles whichare of comparatively rare occurrence. I never found any calcareous pebble in their gizzards, and was often at a loss to explain how the bird was able to ascertain for itself the different degree of hardness between the two pebbles, when the quartz was of the dull white variety. . . . I learn from a recent work on New Guinea by the missionaries, Messrs. Chalmers and Gill, that inside the gizzard of each Goura pigeon there is a good-sized pebble much prized by the natives as a charm against spear-thrusts and club blows.[458]The Goura pigeon resembles the Nicobar pigeon in habits; and I think it probable that its gizzard will be found to present a similar structure and mechanism for cracking nuts and hard seeds. The common fruit pigeons (Carpophaga) of the Solomon Islands, living as they do on soft fleshy fruits, and rejecting the hard seeds and kernels, have no peculiar structure of the gizzard, the walls of which are comparatively thin, and are thrown into permanent rugæ somewhat warty oh the surface.

[458]“Work and Adventure in New Guinea” (p. 317): London, 1885.

One of the most familiar birds in these islands is the “bush-hen,” which belongs to the family of the mound-builders (Megapodiidæ). They bury their eggs in the sand at a depth of between three and four feet. On one occasion in the island of Faro, Lieutenant Heming and his party found eight eggs, in different stages of hatching, thus buried: they were scattered about in the sand; and according to the account of the natives only one egg was laid by each bird. The eggs are sometimes found on the surface of the sand. The young birds are able to fly short distances soon after they are hatched. One that was brought on board astonished us all by flying some thirty or forty yards from the ship and then returning to the rigging.

The account recently published by Mr. H. Pryer of his visit to the birds’ nest caves of Borneo[459]has opened up the discussion as to the nature of the substance of which the edible bird’s nest is composed. Many and varied have been the surmises as to the source of this material; but nearly all of them have been based on mere speculation, and have been relegated to the limbo of sea-tales. Amongst the earlier explanations, I may allude to those which have been given by early writers. The swiftlets (Collocalia), which build their nests in this extraordinary fashion, were considered to gather a gelatinous material from the ocean-foam, or from the bodies of holothurians, or from the skin of the sun-fish. The Chinese fishermenassured Kæmpfer that their nests were composed of the flesh of the great poulpe. A more probable explanation, however, was found by Rumphius in the occurrence on the sea-coasts of a soft almost cartilaginous plant which he with confidence asserted was the material from which these swiftlets constructed their nests; but subsequently this naturalist inclined to the opinion that the substance of which the edible birds’ nests are composed is merely a secretionary product. In these two views of Rumphius we have the two sides of the controversy very much as it at present stands. On the one hand, there are those who hold that this substance is a secretionary product: on the other hand, the opinion is held that the nest is constructed of a vegetable matter, usually resulting from the growth of a microscopic alga, which is found in the caves and on the faces of the cliffs where the nests occur. All the weight of experiment and of actual observation tends to negative the view of the vegetable origin of this substance. Sir Everard Home in 1817 declared his opinion that certain peculiar gastric glands, which he found in one of these birds, secreted the mucus of which the nest was formed. In 1859, Dr. Bernstein[460], after having carefully studied the habits of the birds in question, came to the conclusion that their nests are formed from the secretion of certain salivary glands which are abnormally developed during the nest-building season. M. Trécul, who held the same opinion, showed that the bird constructs its nest by means of a mucus which flows abundantly from its beak at the pairing time.[461]This last view is strongly supported by Mr. Layard, who unhesitatingly pronounces his opinion that these swiftlets build their nests from the secretionary products of their own salivary glands.[462]However, when Mr. Pryer visited in March, 1884, the birds’ nest caves in British North Borneo, he considered that he had found the source of the material of which the nests were composed in the occurrence of a “fungoid growth,” which incrusted the rock in damp places, and which, when fresh, resembled half-melted gum tragacanth. Without at present expressing an opinion as to the validity of the inference Mr. Pryer drew from his observations in these caves, I may observe that the “fungoid growth” has been determined by Mr. George Murray,[463]of the Botanical Department of the British Museum, to be the result of the growthof a microscopic alga, a species, probably new, ofGlœocapsa; whilst the edible nests from these caves, according to a chemical and microscopical examination made by Mr. J. R. Green,[464]have been shown to be formed in the great mass ofmucin, which is the chief constituent of the mucous secretions of animals. After examining various specimens of edible nests from other localities, Mr. Green subsequently confirmed the results of his first experiments. The nest-substance, as he unhesitatingly states, is composed ofmucin, or of a body closely related to it.[465]So far, therefore, there would appear to be but little evidence to support the view of Mr. Pryer that the species of alga, which he found incrusting the rock in the vicinity of the Borneo caves, supplied the material for the construction of the nests of the swiftlets. However, before proceeding to state my own opinion on the matter, I will refer briefly to my observations in the Solomon Islands relating to this question.

[459]Proceedings of the Zoological Society for 1884: p. 532.[460]Journ. für Ornithologie, 1859, pp. 112-115; also Proceed. Zoolog. Soc., 1885, p. 610.[461]“A General System of Botany,” by Le Maout and Decaisne: London, 1873, p. 983.[462]“Nature,” Nov. 27th, 1884.[463]Proc. Zoolog. Soc., 1884: p. 532.[464]Proc. Zool. Soc., 1884, p. 532.[465]“Nature,” Dec. 11th, 1884 and May 27th, 1886.

[459]Proceedings of the Zoological Society for 1884: p. 532.

[460]Journ. für Ornithologie, 1859, pp. 112-115; also Proceed. Zoolog. Soc., 1885, p. 610.

[461]“A General System of Botany,” by Le Maout and Decaisne: London, 1873, p. 983.

[462]“Nature,” Nov. 27th, 1884.

[463]Proc. Zoolog. Soc., 1884: p. 532.

[464]Proc. Zool. Soc., 1884, p. 532.

[465]“Nature,” Dec. 11th, 1884 and May 27th, 1886.

A species ofCollocalia, which usually frequents inaccessible sea-caves and cliffs, is frequently to be observed on the coasts of the islands of this group. The natives of Treasury Island call this bird “kin-kin;” but they have no knowledge of the nutrient qualities of the substance of which it builds its nest, and they were much amused when I told them of its being a Chinese luxury. I only came upon the nests of this bird on one occasion, and that was in some caves on Oima Atoll in Bougainville Straits. A description of these caves will be here unnecessary. As in the instance of the birds of the Borneo caverns, these swiftlets shared their retreats with a number of large bats, the accumulation of whose droppings had produced a thick reddish-brown deposit on the floors of the caves. The nests, which were formed for the most part of fibres derived evidently from the vegetable drift[466]at the mouths of the caves, were thickly incrusted with the gelatinous incrustation which projected as winglets from the sides and fastened them to the rock.

[466]The husks of pandanus seeds more particularly.

A reddish soft gelatinous incrustation occurred on the faces of some of the cliffs in the vicinity of the caves. It was composed of an aggregation of the cells of a microscopic unicellular alga which measure1⁄2500of an inch in diameter. Unfortunately the specimens of this growth which I collected have been mislaid, but there can be little doubt that it is similar to the “fungoid growth” which Mr.Pryer describes in connection with the Borneo caves, and which, through the kindness of Mr. George Murray, I had the opportunity of seeing at the British Museum. On the faces of the coral limestone cliffs of some islands, such as on the east coast of Santa Anna, a like growth occurs in considerable quantity. In its freshest condition, it may be described as a reddish-yellow, gum-like substance forming a layer1⁄4to1⁄8of an inch in thickness. Where it incrusts the overhanging face of a cliff, it is more fluid in consistence and sometimes hangs in little pendulous masses, one to two inches in length, the extremities of which are often distended with water. This alga decomposes the hard coral limestone, making the surface of the rock soft and powdery. All stages in the growth of this substance may be observed. The older portions are very dark in colour and have a tough consistence; and in the final stage it occurs as a black powder covering the rock surface. On examining this alga with the microscope, I found it to be formed almost entirely of granular matter apparently resulting from the death of the cells; whilst the presence of a few cellular bodies alone gave me an indication of its true nature.

From my observations relating to the subject of the edible bird’s nest, it may be therefore inferred that in the Solomon Islands, as in Borneo, the occurrence of these nests is associated with the presence of a protophytic alga, which incrusts the rocks of the locality as a gelatinous or gum-like substance. Whether or not the birds employ this material in forming their nests, is a question which would appear to have been already answered in the negative; but it seems to me that those who hold that this material is used for this purpose might justly claim that the final judgment should be suspended, until a chemical examination of this vegetable substance has been made with the object of determining whether it might not yield a material closely resemblingmucin. Amongst the nitrogenous constituents of plants occurs the so-calledvegetable albumen, which in its chemical composition and in its behaviour with re-agents does not differ materially from theblood-albumenof the animal organism, of which in fact it is the source. In suggesting, therefore, that avegetable mucinmay be found in this low plant-growth, I do not pass beyond the bounds of probability.[467]

[467]Videa letter by the writer in “Nature,” June 3rd, 1886.

Small scorpions came under my notice in Faro Island. They are not usually more than 11⁄2in length and occur in narrow clefts ofrocks and in the crevices of trees. I was stung by one on the thumb, but the pain was trifling and soon passed away.[468]

[468]Specimens of these scorpions were given by me to the Australian Museum, Sydney.

A species ofIulusor Millipede, which attains a length of from 6 to 7 inches, is commonly found in the eastern islands of the Solomon Group on the trunks of fallen trees and amongst decaying vegetable débris. It is often to be seen amongst the rotting leaves that have gathered inside the bases of the fronds of the Bird’s-nest Fern (Asplenium nidus). These Myriapods seem to be less frequent in the islands of Bougainville Straits towards the opposite end of the group, as I do not remember seeing any largeIuliin that locality: their place appears to be taken by another Myriapod, apparently aPolydesmus, growing to a length of 21⁄2inches, which I found amongst decaying vegetation at all elevations up to 1900 feet above the sea, as on the summit of Faro Island. But to return to theIuli, I should remark that this genus of Myriapods evidently possesses some means of transportal across wide tracts of sea, since, amongst other islands similarly situated, it is found in Tristan da Cunha,[469]in the South Atlantic Ocean, and I have found it in the Seychelles, in the Indian Ocean. The habits of these Millipedes would render it highly probable that they have reached the oceanic islands on vegetable drift, such as floating logs. It is, however, a noteworthy circumstance that they do not seem to be able to withstand immersion in sea-water for any length of time. In experimenting on the Solomon Island species, I found that they were able to survive an hour-and-a-half’s complete immersion in sea-water, but that an immersion of three hours killed them. One individual, out of several experimented on, survived for twelve hours after it was taken out, but only in a half lifeless condition.[470]It may, therefore, have been that theIulushas been transported to oceanic islands by such agencies as canoes and ships, rather than by means of floating trees.[471]

[469]Moseley’s “Naturalist on the Challenger,” p. 134.[470]This species ofIuluswas able to sustain a longer submersion in fresh-water, without apparently any injurious effects. Those experimented on recovered after being kept under water for four hours, but died after a submersion of six hours.[471]As bearing on this point, it might be interesting to determine whether these largeIulioccur on islands far from land which are believed never to have been inhabited.

[469]Moseley’s “Naturalist on the Challenger,” p. 134.

[470]This species ofIuluswas able to sustain a longer submersion in fresh-water, without apparently any injurious effects. Those experimented on recovered after being kept under water for four hours, but died after a submersion of six hours.

[471]As bearing on this point, it might be interesting to determine whether these largeIulioccur on islands far from land which are believed never to have been inhabited.

Like other species of the genus, the Solomon IslandIulusexhales a very pungent and disagreeable odour, which is caused by an acrid fluid secreted by small vesicles, of which each segment of thebody contains a pair.[472]On holding my nose for a moment over the mouth of a bottle, containing two of these large Millipedes, I experienced a strong sensation in the nasal passages, reminding me much of the effects of an inhalation of chlorine gas. I had previously learned from resident traders that these Millipedes have a habit of ejecting an acrid fluid when disturbed, which, if it entered the eye, was liable to cause acute inflammation; and the instance was related to me of the captain of some ship, trading in these islands, who lost the sight of one of his eyes from this cause. Mr. C. F. Wood learned from the natives of St. Christoval, in 1873, that these Myriapods “could squirt out a poisonous juice, which was dangerous if it happened to touch one’s eye;” but he adds, “there seemed no great probability of their doing this.”[473]However, I usually found that native testimony, in such matters, was very reliable; and in the instance of this reputed habit of theIulus, my personal experience has convinced me of its reality. Whilst handling one of these Millipedes as it lay on the trunk of a fallen tree in Ugi Island, I felt a sudden smarting sensation in the right eye, caused apparently by some fluid ejected into it. Remembering the injurious effect attributed to this habit of theIulus, I at once plunged my head under the water of a stream, in which I happened to be standing up to my waist, and I kept my eye open to wash away the offending fluid. During the remainder of the day, there was an uncomfortable feeling in the eye and somewhat increased lachrymation; but on the following morning these effects had disappeared. At the time of this occurrence, my face was removed about a foot from the Millipede; and, although I was uncertain from what part of the body the fluid was ejected, I did not care, under the circumstances, to continue the inquiry.

[472]Hoeven’s Zoology. (Eng. edit.) Vol. I., p. 291.[473]“A Yachting Cruise in the South Seas,” p. 131. (London, 1875.)

[472]Hoeven’s Zoology. (Eng. edit.) Vol. I., p. 291.

[473]“A Yachting Cruise in the South Seas,” p. 131. (London, 1875.)

Amongst the first living creatures to greet the visitor as he lands on the beach of a coral island in the Pacific, is a small species of Hermit-Crab, belonging to the genusCoenobita, which frequents the beach in great numbers. The crab withdraws itself just within the mouth of the shell, where it forms a perfect operculum, by means mainly of the large flattenedchelæof the left great claw which is arched over by the left leg of the third pair, whilst the right claw and the right leg of the second pair serve to complete the shieldThe most plucky and pugnacious of these little crabs are those which occupy cast-offNeritashells, a character which probably arises from their consciousness of the solid strength of the home they have chosen: and, strange to say, the tiny bosses on the surfaces of the large pincers, which are outermost in the improvised operculum, resemble similar markings on the outer side of the operculum of theNerita(N. marmorata, Hombr and Jacq), whose shell they often inhabit. Mr. Darwin[474]observed that the different species of hermit-crabs, which he found on the Keeling Islands in the Indian Ocean, used always certain kind of shells; but I could not satisfy myself that such was the case in the instance of the Solomon Island hermit-crabs. In the case of the common beach species ofCoenobita, I found, after carefully examining a number of individuals to satisfy myself of their being of the same species, that shells of the generaTurbo,Nerita,Strombus,Natica,Distorsio, Truncatella,Terebra,Melania, &c., &c., contained the same species ofCoenobita, whether the individual was large enough to occupy aTurboshell of the size of a walnut or sufficiently small to select the tiny shell of theTruncatellafor its home. Another species of the same genus prefers usually the vicinity of the beach; but it may occur at heights up to 200 feet above the sea. It is rather larger than the beach species, and differs amongst other characters in the more globose form of the large claws and in the greater relative size of the left one. It occupies shells of different kinds, such as those ofNerita,Turbo, &c. A still larger species, which frequents the vicinity of the beach, usually selectsTurboshells, apparently because of their larger size. All the other species ofCoenobita, which I met with, used, when I touched them, to withdraw themselves within their shells and close them up at once with their claws; but this kind, when I caught hold of theTurboshell that it carried, left the shell behind in my fingers with apparent unconcern and crawled leisurely away, displaying, somewhat indecorously, the rudimentary plates on the back of its abdomen. These are the plates that attain their greatest development in the Cocoa-nut Crab (Birgus latro), which is thus able to dispense with a shell altogether. The greatest heights at which I found hermit-crabs were in the island of Faro on the two highest peaks, which are elevated respectively 1600 and 1900 feet above the sea. In both these localities, the crab had reached the very summit and could not have climbed higher. Thespecies was apparently different from, though closely allied to, the common beach species, and frequented the shells of a land-snail (Helix). I was indebted to Lieutenant Heming for directing my attention to the hermit-crab, found 1900 feet above the sea. It appears to me likely that these hermit-crabs will be found at much greater heights in this group, since, in this island, their ambition to rise had carried them up as far as they could go.

[474]“Journal of the Beagle,” p. 457.

Other species of hermit-crabs, that are common in these islands, belong to the genusPagurus. They are conspicuously distinguished from the species ofCoenobita, above described, by their first pair of claws, which are small and weak and ill-adapted for defensive purposes. For this reason, these species are less able to look after themselves; and since they cannot form the operculum-like shield with their claws at the mouth of the shell, they always choose shells which will permit of their retiring well within it, so as to be out of the reach of their enemies. Some species are found in the stream-courses and in the brackish water near their mouths, when they often frequent cast-offMelaniashells. Other species (?) prefer the sea-water on the reef-flats. I noticed one individual that displayed its eccentricity of disposition, in selecting, as its abode, the hollow tube of a small water-logged stick, about six inches long, which it dragged about after it during its peregrinations, and into which it retreated when alarmed. On one occasion, I observed a largeDoliumshell, moving briskly about in a pool of salt-water, which, on picking up, I found to be tenanted by aPagurus, so ridiculously small, in comparison with the size of the shell, that when frightened it retreated to the very uppermost whorl, and, notwithstanding the wide mouth of the shell, could not be seen. So light was the weight of the crab, that, on account of the buoyancy of its shell, it floated lightly on the surface of the water, on which I had placed it with the mouth of the shell uppermost, and was blown by a slight breeze across a pool of water, some twenty yards in width. While it was afloat, the shrewd little occupant retired to the innermost recess of its home; but as soon as the shell had grounded, it protruded its head and pincers and endeavoured to overturn the shell, which it finally succeeded in accomplishing.

In the case of these two genera of hermit-crabs,CoenobitaandPagurus, it was interesting to notice the relation existing between the defensive capabilities of the crab, and the relative size of the shell it selected as its home. ThePagurus, with its weak slenderpincers, chooses large shells within which it can retire well out of reach when alarmed. TheCoenobita, with its stout pincers, prefers shells much smaller, relatively speaking, and ensconces itself snugly in the body whorl, forming an operculum with its claws. As the hermit-crab,Coenobita, crawls along the dry sand of a beach, it leaves behind it characteristic pinnate tracks which may be often traced for several feet. The lateral markings are produced by the claws and legs working on each side of the shell; whilst a central groove is formed by the weight of the shell itself. As shown by the arrow in thediagram, the lateral markings point in the direction of the course which the hermit-crab has taken. Sometimes only a single row of lateral tracks accompanies the grooves produced by the shell. Such markings were produced by a hermit-crab when frightened by my approach. It turned its front towards me, and crawled backwards, by working most of his claws and legs on one side of the shell. In the case of the larger hermit-crabs, which are much less frequent on the beach, each limb produces a distinct print on the sand; but with the small species ofCoenobitawhich infests the beach, each lateral marking, as shown in the diagram, is produced by a single movement of the claws situated on the same side of the shell. The hermit-crabs only leave their tracks on the dry loose sand. One individual, that I placed on sand, still wet from the retreating tide, crawled along without leaving any impression. I have described these impressions with some care, as they bear on the origin of the surface-markings of rocks of shallow-water formation, a subject recently discussed in the geological world. It is highly probable that some of the larger and heavier forms of the Anomura (and, in fact, of the Decapoda generally) would produce prints such as I have here described, both on mud-flats left dry by the tide, and on the soft bottom in shallow depths. A cast of the impressions thus produced would have an unmistakeable plant-like form.

Track of hermit crab

Whilst examining the island of Simbo, I noticed some singular Medusæ in a small mangrove-swamp, which is inclosed in the low point that forms the south shore of the anchorage. Numbers of these organisms of a large size (8 or 9 inches across the umbrella), and of a dirty-white colour, were lying on the mud with theirtentacles, uppermost in depths of from one to three feet of water. I was struck by the handsome mass of arborescent tentacles which they displayed, and by the peculiarity of their lying upside-down. The dark mud which formed the bottom of the swamp was composed of decayed vegetable matter, confervoid growths, diatoms, and a few infusoria: but when I raised up these Medusæ, I found underneath each a patch of white sand corresponding with the outline of the organism, but completely concealed by the umbrella when the Medusa lay in its usual position. The sand was derived from corals, shells, and the volcanic rocks of the island; and the light patches formed a marked contrast with the dark mud around. I was unable to find any satisfactory explanation of these curious patches of sand; and I, therefore, proceeded to interrogate the Medusæ on the subject by watching them, but to no purpose. So I had my revenge by turning them all over on their tentacles, when each one immediately began to contract its umbrella in a most methodical fashion, and, after swimming a short distance, deliberately resumed its former position of tentacles upward. I had an extensive experience of mangrove-swamps after we left Simbo; but these self-willed Medusæ never came under my notice again.[475]

[475]I referred to the habits of these Medusæ in “Nature,” Nov. 9th, 1882.

With regard to these Medusæ, I should remark that they belong to a species ofPolyclonia, and are classed amongst the Scypho-Medusæ.[476]Two species ofPolycloniaseem to be known,P. frondosa(Agassiz) andP. Mertensii(Brandt), the first found in the Florida seas, and the latter in the Carolines. I am inclined to think that the Solomon Island species is more nearly allied toP. Mertensii. Both species, however, have similar habits, lying on the mud of mangrove-swamps, with their tentacles uppermost.

[476]I compared my notes with the description and figures given by Agassiz in his “Contrib. Nat. Hist. U.S.A.” (1862: vols. iii. and iv.). In the Solomon Island species, the dendriform mass resolves itself into 8 principal branches, each ramose, and all united at their bases by a common membrane. The umbrella, which was finely lobed or crenulated at its margin, displayed about 40 radiating canals, each communicating by an anastomosing network with the canal on either side of it.

The singular habits of these Scypho-Medusæ were noticed by Brandt in 1838. They have since been remarked by Mosely[477]in the Philippines, and by Archer[478]in the West Indies. L. Agassiz in his “Contributions to the Natural History of the United States,” describes and figures the Florida species (Polyclonia frondosa); andsome additional notes on its habits have been made by A. Agassiz, to whose communication in “Nature” (Sept. 29th, 1881) I have been much indebted.

[477]Mosely’s “Notes by a Naturalist,” p. 404.[478]“Nature” Aug. 4th, 1881.

[477]Mosely’s “Notes by a Naturalist,” p. 404.

[478]“Nature” Aug. 4th, 1881.

Whilst we lay at anchor in Treasury Harbour, in April, 1884, a cetacean, unknown to the natives and to ourselves, got partly stranded in the shallow water, and was captured by the villagers. It was nine feet long, and possessed this remarkable character that, although no teeth showed through the gums, each lower jaw possessed a short, conical, hollow tooth an inch long, placed at the anterior extremity. I obtained the head from the natives, and placed it in a safe place, as I thought; but when we returned to Treasury a few weeks after, I found only portions of the skull with the lower jaw-bones, the wild pigs having held a feast over it. The remains, however, together with my notes and a sketch by Lieutenant Leeper were sent to the British Museum. I there learned that it is a species of Ziphius, probably unknown.

The Solomon Islanders believe in the existence of anthropoid apes in the interiors of the large islands, regarding them, however, like the Dyaks of Borneo in the case of the Orang-utan, as “wild men of the woods.” In Malaita they are said to be 41⁄2to 5 feet high, and to come down in troops to make raids on the banana plantations. Captain Macdonald informed me that the natives allege that one of these apes was caught, and, after being kept for some time, escaped. Taki, the St. Christoval chief, told Mr. Stephens that he had seen one of these apes, and pointed out the locality. Tanowaio, the Ugi chief, also made a similar statement. In Guadalcanar, they are believed to live in the trees, and to attack men. Dr. Codrington refers to the prevalence of these beliefs throughout Melanesia (Journ. Anthrop. Inst., vol. x. p. 261). Such beliefs, as experience has shown in the case of the Gorilla and other anthropoids, have undoubtedly some foundation; but whether these mysterious animals are apes is quite another question.

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