Chapter 47

DENTITION OF DESMAN.

The Desman, or Wychuchol of the Russians, is an inhabitant of Southern Russia, where it lives in the banks of streams and pools, in the region between the Don and the Volga. It is also said to occur in some parts of south-western Asia. Its body is about ten inches long, and its tail measures about seven inches and a half. The latter organ is narrowed at the root, and then nearly cylindrical for some distance, and finally compressed from near the middle to the extremity, thus forming a most powerful swimming organ, by means of which, aided by the broad webbed feet, the Desman makes its way through the water with great rapidity. The surface of the tail is scaly, with a scanty sprinkling of short hairs, and with a great number of small follicles, which secrete a greasy material.

The body of the Desman is covered with a dense fur, composed of a thick coat of fine downy hairs next the skin, and of longer smooth hairs, which form the outermost coat. It is reddish-brown on the back, ashy-grey on the belly, and shows a silvery lustre in certain lights. The feet are naked and scaly above, and fringed with hairs at the sides. At the eye, and over the auditory aperture, there are whitish spots.

In its habits the Desman is described as greatly resembling an Otter on a small scale. It lives by preference about standing waters and slow streams, especially when these, as is so commonly the case in Russia, are confined by steep banks of considerable height. In these banks it makes its residence, which is something like that of the Otter, consisting of a passage running obliquely upwards from below the surface of the water, often to a length of twenty feet or more, and then terminating in a sort of fortress-chamber, three or four feet above the water level. But this retreat is only occupied by the animal as a resting place; the greater part of its time, both in summer and winter, being passed in the water. Here it disports itself with an agility of which its rather heavy and clumsy figure would hardly appear to give promise; swimming and diving readily, making its way among the water-plants, and seeking constantly for the animals which constitute its food. These are chiefly leeches, worms, and aquatic mollusca and larvæ of insects, but in all probability no small aquatic animal would come greatly amiss. The curious movable trunk with which the animal is endowed is brought actively into play during the search for provisions. It is turned and twisted in various directions, touching the various objects that come in the way, and is used to feel about for prey, which it is said to seize and convey to the neighbouring mouth after the same fashion as the trunk of an elephant. The animal is said frequently to put its trunk into its mouth, and then to cry like a duck; when irritated or threatened, it hisses, and tries to bite. The Desman is supposed to produce more than one litter in the course of the year. It is pursued for the sake of its skin, which somewhat resembles that of the Beaver and Ondatra in its qualities; and great numbers are taken by means of nets, especially in the autumn. Its flesh is uneatable, on account of its strong musky flavour, which is communicated even to that of the carnivorous fishes, such as the Pike, which, being less nice in their tastes, do not object to an occasional Desman.

The only other species of Desman is found in the small streams of the Pyrenees both in France and Spain, where it lives after the same fashion as its Russian relative, but is said to feed principally upontrout. It is much smaller than the preceding species, being only ten or eleven inches in total length, nearly one-half of which is occupied by the long tail. The fur is chestnut-brown on the back, greyish-brown on the sides, and silvery grey on the belly; the upper lip bears some pectinated whiskers, the sides of the trunk are covered with white and the fore-feet with brownish hairs; while the hind-feet are naked and scaly. This animal also diffuses a strong musky odour.

Besides the true Desmans this group is considered to include two or three singular little creatures which lead directly towards the true Moles. One of these is a Japanese species, discovered by Professor Siebold, and described by Professor Temminck under the name ofUrotrichus talpoides, which we may call the Hairy-tailed Mole-Shrew. It differs from the Desmans, and agrees with the true Shrews in having only two incisor teeth in the lower jaw. There are thirty-eight teeth in all. It is about the size of the common Water Shrew, with the nose greatly elongated, not into a flexible proboscis, but into a snout with the nostrils placed at the sides of the tip; the tail is about an inch long, stout, scaly, and covered with long hairs, which form a tuft; the fur is brown and velvety, and the snout and feet flesh-coloured, and nearly naked.

This animal is common at elevations of from 1,000 to 1,200 feet in the mountains of the southern and eastern parts of Japan, but becomes more rare towards the north. In its habits it resembles the Moles, digging out galleries in the earth, but going down deeper, and rarely if ever forming heaps of loose earth at the surface.

A nearly allied species, Gibbs’ Mole Shrew (Urotrichus Gibbsii), is found in North America.

Another species, leading more towards the Shrews, was discovered in eastern Tibet by the Abbé David, and described by M. A. Milne-Edwards under the name ofUropsilus soricipes, or the Shrew-footed Uropsile. The general characters of the animal are very like those ofUrotrichus, but it has one premolar less on each side in each jaw, making the total number of teeth only thirty-four. The tail is naked and scaly; and the fur is of a slate-colour, with a slight brownish tinge.

A great number of small mouse-like and rat-like animals, presenting shades of character which render their classification almost insuperably difficult, constitute the family of the Shrews, which, as we have already stated, may be regarded as representing the generalised or central idea of the Insectivorous Mammal. On all sides the other families include anomalous species, and the characters which distinguish these from their immediate fellows generally tend in the direction of the Shrews.

In these creatures we find a mouse-like body, terminated in front by a small head, with a long pointed muzzle, and behind by a nearly naked, scaly tail of variable length. The eyes are small, as also are generally the ears; the limbs are short, and nearly equal in size; the skull is long and narrow, and has on each side of its base a space not filled up with bone; the teeth are from twenty-eight to thirty-two in number, and the middle incisors in both jaws are very large; the skull has no zygomatic arch or tympanic bony bubble; the bones of the shank (tibia and fibula) are united; and the intestine has no cæcum. On the sides of the body or at the root of the tail the Shrews possess peculiar glands, which secrete a fluid of strong odour, serving no doubt to protect them from many enemies.

The Shrews are distributed over all parts of the Old World and in North America. They live generally on the ground, although some take freely to the water, and they feed upon worms, insects, and other small animals such as they can overcome. The difficulty of classifying these animals to which we have already alluded has led to their being divided into an infinity of generic groups, of which we shall endeavour to illustrate those which are now most generally accepted.

The Common Shrew, or Shrew-mouse, as it is often called, may be noticed first, as being the species most likely to be met with by our readers, in England at any rate. It is one of the species for which the Linnæan generic nameSorexhas been retained, the group as restricted including Shrewswith from thirty to thirty-two teeth, there being four or five premolars in the upper and only two in the lower jaw; with a basal tubercle to the upper inner incisors; with ears of moderate size directed backwards, a long tail, and the feet not fringed with hairs.

1. PIGMY SHREW. 2. COMMON SHREW. 3 AND 4. WATER SHREW.❏LARGER IMAGE

1. PIGMY SHREW. 2. COMMON SHREW. 3 AND 4. WATER SHREW.

❏LARGER IMAGE

Our Common Shrew is a pretty little mouse-like creature (its figure will be seen inPlate 12), measuring about two inches and three-quarters in length, with a tail rather more than an inch and a half long. Its fur is generally of a reddish-grey colour above, and greyish beneath; but the colour varies considerably, being sometimes blackish or chestnut above, and tinged with yellow beneath. The fore teeth are of a rich brown colour. The tail is four-sided,[281]with the angles rounded off, and is nearly of equal thickness throughout; it is covered with short, close, stiffish hairs. Mr. Bell states that the Shrew sometimes occurs spotted with white, and that he possesses one specimen “which is beautifully pied, having a broad white band over the loins, which extends all round the animal.”

DENTITION OFCOMMON SHREW.

The food of the Common Shrew consists chiefly of insects and worms, but it also eats the smaller mollusca, and even the common Slug (Limax agrestis), according to Mr. Bell, who says that he has not only found the remains of that animal in its stomach, but has also fed it upon slugs in confinement. Like its ally, the Mole, it is very pugnacious, and two Shrews rarely come together without a battle, when the weaker one is killed and eaten. The breeding season of the Shrew is in the spring, when the female makes a comfortable nest of soft dry herbage in some convenient hole in the ground, and there brings forth from five to seven young ones. Their increase is checked to a certain extent by natural enemies. Thus, the Mole is said to kill and eat them when they come in his way; and Cats, Weasels, Owls, and some other animals, will also kill them; and some at least do not disdain to make a meal upon them. The Barn Owl especially seems to make great havoc among the Shrews.

All sorts of evil qualities were attributed to the Shrew by our ancestors, some of which are still believed in. One old writer says that the Shrew-mouse is “a kind of Field-mouse of the bigness of a Rat and colour of a Weasel, very mischievous to cattel; which, going over a beast’s back, will make it lame in the chine; and the bite of it causes the beast to swell at the heart and die.” The running of a Shrew over the leg of a beast was generally believed to cause the latter great pain, and to produce lameness. The proper cure for these imaginary ills was on a par with the mischief; the remedy was the application to the part affected of a branch or twig of a shrew-ash, which, says Gilbert White, “was made thus: into the body of the tree a deep hole was bored with an auger, and a poor devoted Shrew-mouse was thrust in alive, and plugged in, no doubt with several quaint incantations since forgotten.”

There is one circumstance in the natural history of the Shrew that must have struck everybody, although it is still entirely unexplained. This is the death of great numbers of these animals in autumn without any apparent cause. Residents in the country will know that at that season Shrews may be seen lying dead on almost every footpath; in fact, the observation is so general as to have given rise to another superstition, namely, that a Shrew cannot cross a public path without paying the penalty of death. The individuals thus found dead are of both sexes, and of various ages.

The Common Shrew occurs not only in the British Islands, but also over the whole continent of Europe, from Sweden and Russia to the shores of the Mediterranean.

The Lesser Shrew (Sorex pygmæus, whose figure will be seen inPlate 12) is a second British species nearly allied to the preceding, but smaller, measuring rather less than two inches in length, and with a proportionately longer tail. The lower parts of the body are also whiter. It is the smallest of British Mammals.[282]

Some small species of American Shrews agree with the restricted genusSorexin the number ofteeth, but have no lobe at the base of the upper incisors; the external ear is small, turned forward, and the tail short, usually not longer than the head. These form the genusBlarina.

Dekay’s Shrew is about four inches and a half long, and the tail about an inch. Its fur is of a rusty yellow-grey colour above, paler beneath; the nose and feet are reddish-brown, and the front incisors black. From Dr. Bachman’s description it would appear that this animal burrows rather deeply in the ground, after the fashion of the Mole. It is found in the northern United States.

A very considerable number of Shrews, distributed in all parts of the Old World, and including two or three well-known European species, have been formed into the genusCrocidura, which in its turn has been divided again and again by means of characters generally of very slight importance.

TheCrociduræhave from twenty-eight to thirty teeth, all white, or with white tips; the lower incisors are not toothed; the teeth between the incisors and the molars in the upper jaw gradually decrease in size; and the tail is covered with short hairs, among which there are a good many longer ones.

The Garden Shrew (Crocidura aranea) is a small species, usually measuring a little over four inches in total length, of which the tail occupies about an inch and a third. It has twenty-eight teeth which are all white. The fur is of a mouse-grey colour, shading off into whitish ash on the lower surface; the feet are light ashy, with the toes flesh-coloured, as is also the tip of the snout; and the ears, which are well exposed, are ash-coloured above and whitish below. The fur occasionally has a reddish-brown tinge; and, as in the Common Shrew, specimens spotted with white, and even albinos, sometimes occur. This is a common species almost all over Europe, but does not occur in Sweden or in the British Islands. It lives in woods and plantations, in the fields and in gardens, and in the winter approaches close to the houses, sheltering itself under stones and other objects, and sometimes even entering stables and other outbuildings. Like the other species, it feeds upon insects, worms, and other small animals, and like them also it has the reputation of injuring domestic animals by walking over them.

The Tuscan Shrew (Crocidura etrusca) is another well-known European species, but its distribution is much more limited than that of the Garden Shrew. It is found generally in the extreme south of Europe, from France to the Black Sea, and also in the north of Africa, but does not appear to extend north of the Alps. Like the Garden Shrew, it frequents gardens, and not unfrequently comes into houses and outbuildings. In the open country it selects dry and warm situations.

The total length of the Tuscan Shrew is from two inches and a half to two inches and three-quarters, and as the tail is nearly an inch long, the head and body may measure little more than an inch and a half. It is the smallest of living Mammals. The teeth are thirty in number. The colour of the fur is ashy with a reddish tinge above, light ashy beneath; the tail is clothed with short hairs, and with a series of rings of longer white hairs; and the ears are of moderate size, projecting distinctly from the fur. In its habits it agrees with the other species.

Amongst a number of Indian species, some of which are of doubtful distinctness, we may notice one which seems to be widely distributed in the East, and well known in India and elsewhere, under the name of the Musk Shrew, or Musk Rat. It is usually of a dark brown or even blackish colour above, and much paler beneath, but it varies considerably in this respect, and thus has probably given origin to several so-called species. The ears are of considerable size, and the tail, which is about three-fourths the length of the body, is thickened towards the root—a character of the sub-genusPachyura. The animal is about six inches long. It is a very common Indian species, and frequents houses at night, hunting round the rooms in search of the Cockroaches and other insects which abound there. From time to time it utters a sharp, shrill cry. Its musky odour is exceedingly strong, and is said to impregnate everything that the animal passes over; in fact, the popular belief in India is that in running over a bottle of wine or beer, it is capable of infecting the contents! This, however, is rather more than doubtful. Mr. Jerdon distinguishes two species—an Indian one which he callsSorex cœrulescens, which is usually of a bluish ash colour, and a somewhat smaller species, chiefly inhabiting Further India and China, to which he gives the Linnæan name ofSorex murinus. If they are distinct, itis probably to the latter that Mr. Swinhoe refers in his notes on Chinese Mammals under the name the “Musk Rat.” He says that it is found throughout China, Formosa, and Hainan, in houses in large towns, being carried about in junks with the cargo. It has an unpleasant musky odour, and makes a peculiar chattering noise, which sounds like the chinking of money, and, he adds, often disturbed him in his room at night. Such a sound heard in the dark in a strange place would certainly be rather alarming to any one who had money to lose.

RAT-TAILED SHREW.

The “Musk Rat” of Ceylon is a reddish species, described by Kelaart asSorex kandianus, and by Mr. Jerdon asS. serpentarius. It is rather smaller than the preceding, but takes its place in the houses of Ceylon and Southern India, and renders itself equally offensive by its strong musky odour.

Several other Indian species are referred toCrocidura, one of which,C. Perroteti, is said to be even smaller than the Tuscan Shrew. Others occur in Africa, in Egypt, Mozambique, and Madagascar, and in the neighbourhood of the Cape.

Our British Water Shrew is the type of a distinct genus, all the species of which appear to haunt the margins of water. They have thirty teeth, all of which are tipped with brown or red. The upper front teeth are large and curved, and have a basal cusp behind; the lower ones are nearly horizontal, and have a single tubercle and no notch at the tip. Behind these teeth there are on each side in the upper jaw four small teeth, the last of which is very minute; and in the lower jaw two small teeth. The molars are four on each side in the upper, and three in the lower jaw. The snout is pointed, and furnished with very long whiskers; the eyes small; the ears of moderate size, and valvular; and the feet and lower surface of the tail fringed with stiff hairs.

Our Water Shrew (its figure will be seen inPlate 12), which measures about three inches and one-third in length, and has a tail rather more than two inches long, is generally nearly black on the upper surface and white beneath, the colours being usually separated by a distinct line of demarcation. The hairs fringing the feet and the lower surface of the tail are white. There is, however, considerable variation in the colour of different specimens, some of which have been described as distinct species. One especially, in which the whole of the fur is of a black colour, has been called the Oared Shrew (Sorex ciliatusorremifer), but the existence of intermediate steps has led to the recognition of the identity of even this with the Common Water Shew. Mr. Bell is of opinion that the differences ofcoloration depend on the season and the age of the specimen. The tail is slender, four-sided, and compressed towards the tip. The Water Shrew is distributed over the whole continent of Europe, as far north as the shores of the Baltic. It is found in many localities in England and in Scotland, but is not known to occur in Ireland.

The Water Shrew is one of the prettiest of our British Mammals. Its movements, especially in the water, are very agile; and although, from its swimming by alternate strokes of its hind feet, its course is of a somewhat wriggling character, the peculiar mode in which it flattens its body so as to show a narrow white border on each side, and the silvery lustre of the coat of air-bubbles which adheres to its back, give it a very elegant appearance when thus engaged. It is found chiefly about the rivulets of mountainous and hilly countries, generally showing a preference for those quieter parts where the water flows smoothly over a sandy bottom, but it will also make its way through more broken water, in shallow parts full of stones. Clear water seems to be the great desideratum, and if this can be secured the Water Shrew will put up with a lake or pond. It is not, however, absolutely confined to the water-side, but will at times wander about the fields, sheltering itself under haycocks, and other heaps of dried plants, and even making its way into houses, barns, and outbuildings.

Nevertheless, as may be judged from the fringed tail and feet, it is essentially an aquatic animal, and its regular habitation seems to be always constructed in the immediate vicinity of water. Here the Water Shrew burrows into the soft ground of the bank, and forms a subterranean dwelling, usually with several openings, one of which is situated beneath the surface of the water, to give the little creature an opportunity of slipping quietly and unperceived into or out of its house. Its food is principally obtained in the water, and consists of aquatic insects, worms, mollusca, and crustacea, which it snaps up in its rapid fittings to and fro. In Bell’s “British Quadrupeds” the pursuit of the Freshwater Shrimp (Gammarus pulex) in a shallow but rapid streamlet by the Water Shrew is described. The little animal was seen busily pushing about among the stones at the bottom of the water, sometimes poking its nose under them, sometimes turning them over in a fashion which might be thought beyond its strength. The result was the same in either case; the Shrew captured some small article of food, with which it made off to the side of the stream, where it was heard crunching the crustaceans between its teeth.

Besides this small prey, the Water Shrew is said by Continental writers to attack almost any small animal that comes in its way—frogs, fishes, and even small birds and quadrupeds are described as among its victims. It is also said to feed on the spawn of fishes, and, according to Brehm’s testimony, will even destroy large fish, such as Carp, by eating out their eyes and brains. Carrion and dead animals will also furnish it with a meal. One of Mr. Bell’s editors gives a striking instance of this. A steel rat-trap had been set, and in the morning contained a large Rat, “on which was perched a small black object, which proved on closer approach to be a Water Shrew. The Rat was dead, and the Shrew was devouring it. Although the slender snout and projecting and comparatively weak teeth of the Shrew were but ill adapted, one would have thought, for devouring prey of the size of a full-grown Rat, yet the animal had succeeded in making a small hole through the skin, and this it was most energetically employed, by means of both teeth and claws, in enlarging. So ferocious were its actions, that it might very properly be said to befightingthe Rat; and so intent was it on its work as to suffer itself to be captured by the observer, who laid the loading-rod of his gun across its back.”

The breeding season begins in April or May, when the courtship of the little creatures commences by a persevering pursuit of his intended partner by the male. The lady exhibits a becoming coyness, leading her suitor a long chase through the water; but while thus engaged both parties keep the main chance in view, and seize everything eatable that comes in their way. The young are brought forth in a chamber in the bank, and are from five to seven or eight in number.

A nearly allied, but larger species, the Himalayan Water Shrew (Crossopus himalaicus), occurs in the streams of the Himalayas. Mr. Jerdon, who obtained it from the Little Rungeet River at Darjeling, describes it as five or six inches long, dark brown or blackish above, paler beneath, and with a bunch of hairs at the tip of the tail. It was said to kill small fish, tadpoles, aquatic insects, &c. Another species (C. platycephalus) inhabits Japan.

The Marsh Shrew (Sorex palustris), of North America, has bean referred to this genus by some authors; but it has a long slender, cylindrical tail, with a pencil of hairs at the tip, and ProfessorBaird refers it to the genusSorex. The teeth are the same in number as inCrossopus, and likewise have their tips reddish-brown. This species inhabits the northern parts of North America up to Hudson’s Bay Territory.

This is another of the Mammals for the knowledge of which we are indebted to the Abbé David, and it is one of the most curious species of this family, presenting a combination of characters peculiar to itself with those of the True Shrews and the Desmans. “Its head and skull,” says M. A. Milne-Edwards, “refer this animal to theSoricidæ, whilst its palmated feet and compressed tail indicate close affinities with theMyogalidæ; but the sucking discs with which the lower surfaces of its feet are furnished belong to itself alone, and nothing of the same kind is to be found in the allied groups.”

In some respects the Tibetan species is allied to the European Water Shrew, but it has only twenty-eight instead of thirty teeth, namely, incisors,3–31–1, canines,1–11–1, molars,4–44–4; the skull is flattened; the body robust, and supported on short limbs; the muzzle short, broad, and conical, with large whiskers at the sides, and the nostrils opening laterally near the extremity; the eyes exceedingly small; and the ears entirely concealed by the hair and quite destitute of a conch. The tail is stout, longer than the body, quadrangular at the base, then triangular, and finally flattened at the sides; and the feet are large and broadly palmated, so as to form vigorous swimming organs, very closely resembling those of the Desmans. As in the latter animals, the feet are fringed with stiff hairs of peculiar construction; but the nails, which in the Desmans are strong, are here small and weak. The sucking discs, already mentioned as peculiar to this animal, are certainly among its most remarkable characteristics. They occur upon the feet of both pairs, and consist of large pads, depressed in the middle to form cups, which are doubtless of service to the animal in its aquatic mode of life.

The Tibetan Water Shrew is rather a large species, measuring, when adult, nearly eight inches in total length, more than half of which, however, is occupied by the tail. It is thus much larger than the British Water Shrew. Its body is covered with hair of two kinds. Close to the skin is a very thick soft down of a slaty grey colour, through which pass numerous longer hairs, which are grey at the base and white at the extremity, causing the animal to vary considerably in appearance, according as these longer hairs are raised or laid flat. The lower parts of the body are white.

In its compressed tail and largely webbed feet this Shrew possesses most admirable instruments for progression in the water; in fact, it must be regarded as the most thoroughly aquatic of all the family of the Shrews. According to its discoverer, it lives habitually on the banks of the impetuous torrents which descend from the mountains of Moupin in Tibet; and notwithstanding the rapidity of these streams, it swims and dives in them with the greatest facility, chasing the small fishes which constitute its principal food. Although not uncommon in its native region, its activity in the water renders its capture exceedingly difficult. In order to procure specimens, it is necessary to divert the course of a stream, and then pursue the animals into the holes in which they take refuge.

Another curious little Mammal, brought from Tibet by the Abbé David, is described by M. A. Milne-Edwards as forming a distinct genus, under the name ofAnurosorex, or the Tailless Shrew. It has only twenty-six teeth in all, namely, incisors,2–21–1, canines,1–11–1, and molars,4–44–4. The tail is remarkably short, scarcely passing beyond the hairs of the body, slender, slightly flattened, of the same thickness throughout, and covered with small scales, from between which project a few very short hairs. The general form of the body is mole-like, the head is large, the muzzle conical, flesh-coloured, having the nostrils on each side near its extremity, and furnished with long whiskers. The eyes are scarcely perceptible, and the ears are entirely concealed beneath the hairs. The feet are short and scaly, whence the name given to the species, and the fore-feet are broader and stronger than the hind-feet, thus furnishing all additional indication of affinity to the Moles.

This species was found abundantly both in the Plains and mountains of Setchouan and Tibet,where it lives in burrows which it digs in the earth. Its total length is little more than four inches, and its fur, which is very silky and thick, is of a grey colour with a greenish brown tinge. The feet are whitish and the nails white.

In the preceding sketch of the Insectivorous order of Mammals, we have followed in general the classification proposed by Professor Mivart, and slightly modified by Mr. Gill. The following summary of the arrangement will be useful for reference:—

SUB-ORDERI.—DERMOPTERA.Family 1. GALEOPITHECIDÆ.Genus—Galeopithecus.SUB-ORDERII.—INSECTIVORA VERA.Family 2. TUPAIDÆ.Genera—Tupaia, Ptilocereus, Hylomys.Family 3. MACROSCELIDÆ.Genera—Macroscelides, Petrodromus. Rhynchocyon.Family 4. ERINACEIDÆ.Genera—Erinaceus, Gymnura.Family 5. CENTETIDÆ.Genera—Centetes, Hemicentetes, Ericulus, Echinops, Oryzorictes, Solenodon.Family 6. POTAMOGALIDÆ.Genus—Potamogale.Family 7. CHRYSOCHLORIDÆ.Genera—Chrysochloris, Chalcochloris.Family 8. TALPIDÆ.Genera—Talpa, Parascaptor, Mogera, Scaptochirus, Scaptonyx, Condylura, Scalops, Scapanus.Family 9. MYOGALIDÆ.Genera—Myogale, Urotrichus, Uropsilus.Family 10. SORICIDÆ.Genera—Sorex, Blarina, Crocidura, Crossopus, Nectogale, Anurosorex.

SUB-ORDERI.—DERMOPTERA.

Family 1. GALEOPITHECIDÆ.

Genus—Galeopithecus.

SUB-ORDERII.—INSECTIVORA VERA.

Family 2. TUPAIDÆ.

Genera—Tupaia, Ptilocereus, Hylomys.

Family 3. MACROSCELIDÆ.

Genera—Macroscelides, Petrodromus. Rhynchocyon.

Family 4. ERINACEIDÆ.

Genera—Erinaceus, Gymnura.

Family 5. CENTETIDÆ.

Genera—Centetes, Hemicentetes, Ericulus, Echinops, Oryzorictes, Solenodon.

Family 6. POTAMOGALIDÆ.

Genus—Potamogale.

Family 7. CHRYSOCHLORIDÆ.

Genera—Chrysochloris, Chalcochloris.

Family 8. TALPIDÆ.

Genera—Talpa, Parascaptor, Mogera, Scaptochirus, Scaptonyx, Condylura, Scalops, Scapanus.

Family 9. MYOGALIDÆ.

Genera—Myogale, Urotrichus, Uropsilus.

Family 10. SORICIDÆ.

Genera—Sorex, Blarina, Crocidura, Crossopus, Nectogale, Anurosorex.

Only in one respect have we thought it desirable to depart from Professor Mivart’s system, namely, in raising the Desmans (Myogalidæ) to the rank of a distinct family. This course was adopted for the sake of simplicity in the classification, as the combination of characters presented by those animals places them so remarkably between the Moles and the Shrews, that from a zoological point of view they cannot satisfactorily be referred to either.

One thing that will strike the reader at once is the great number of family types, for the most part strongly characterised, that can be distinguished in so small an order. Mr. Wallace estimates the total number of species of Insectivora at 135, and of these about 65, or nearly one-half, belong to the single family of the Shrews, leaving about 70 species for all the other families; and of these 34 species, or again nearly one-half, are referred to the two widely distributed groups the Hedgehogs and the Moles.

Considering these facts, and the clear differentiation of most of the forms, notwithstanding the existence of those types already alluded to, which in several of the families seem to lead towards theSoricidæ, we can hardly avoid agreeing with Mr. Wallace in regarding the existing Insectivora as “the detached fragments of a much more extensive group of animals, now almost extinct,” a view which is strongly corroborated by the geographical distribution of the animals.

Curiously enough several of the smaller and more peculiar families are limited much in the same way as the Pteropine Bats and Lemurs, chiefly to the countries surrounding the great Indian ocean, beneath which, as we have already stated, the hypothetical continent of Lemuria is very probably submerged. The Galeopithecidæ and Tupaiidæ are almost confined to the Malayan region, and the Centetidæ (with the exception of the anomalous genusSolenodon) are peculiar to Madagascar; the Macroscelididæ have their home on the eastern coast of Africa, except a single species which occurs in the northern part of that continent; the Chrysochloridæ are exclusively South African; and the curiousPotamogaleinhabits some of the West African rivers. Thus, except in the case ofSolenodon, the whole of these groups are now represented solely within the region inhabited by the Pteropine Bats. Does this point to a “Lemurian” origin, or at any rate to a great former development in the Lemurian land, of the Insectivorous Mammalia?

Of the more widely distributed families, the Erinaceidæ occur chiefly in the northern temperate regions of the Eastern hemisphere, stretching away continuously from Europe and the North Africandeserts, through Asia Minor and Persia, and across Central Asia to the Pacific Coast, whilst one or two species occur in South Africa, and one very aberrant form, the Bulau (Gymnura), is found in the Malayan region, along with the Bangsrings, to which it is allied through the genusHylomys. The true Moles and the Shrews occur in the northern parts of both hemispheres, and the latter family, indeed, is represented in all parts of the world except South America and the Australian region. The Desmans, which stand in so peculiar a position between the Shrews and the Moles, present a curious instance of what has been called “discontinuous distribution,” the two nearly allied species being found only in two localities, separated from each other by the whole breadth of the European continent. The entire absence of Insectivora from the South American continent, and the presence of the Solenodons, which seem to be most nearly related to the Centetidæ of Madagascar, in Cuba and St. Domingo, are further remarkable facts in the geographical distribution of these animals. Scarcely less singular is the distribution of the two species ofUrotrichus, one of which occurs in Japan, and the other on the Pacific coast of North America.

The evidence derived from the fossil remains of Insectivora, as to the former history of the order, in its bearing upon the present geographical distribution of its members, is very inconclusive; but the principal facts to be gathered from it is that from Miocene times to the present day the representatives of the order in different localities, so far as these are known, have generally belonged to the same types, and no undoubted remains of Insectivora are known from earlier formations than the Miocene. At one time, indeed, some of the beautiful Mammalian fossils of the Stonesfield slate (Lower Oolite) of Oxfordshire were regarded as probably representing Insectivora, but their Marsupial character is now generally recognised; and this is the case also with theDromotheriumfrom the Trias of North Carolina, which was at one time believed to carry the present order so far back in time.

Species of the existing generaErinaceus,Sorex,Myogale, andTalpa, and of several nearly-allied extinct genera, have been determined from Miocene and subsequent deposits in various parts of Europe, and especially from the lacustrine beds of the Auvergne; and in North America also a few species have been found and referred to genera for the most part almost identical with those still living on that continent. In some instances even the Miocene species appear to be nearly identical with those now inhabiting the same regions.

The principal apparent exceptions to this rule are to be found in a fossil species from the Miocene of the Auvergne, described by M. Pomel under the name ofEchinogale Laurillardii(Centetidæ), and two forms described by Hermann von Meyer, as forming a new genus (Oxygomphius), allied to the Bangsrings, from the Tertiary basin of Weisenau, in Southern Germany. But the true position of these fossils is, to say the least of it, exceedingly doubtful; and this is still more strikingly the case with the Eocene American genusOmomyssupposed to be an animal allied to the Hedgehogs and the Bangsrings, but which Professor Leidy himself, in describing it, compares with nearly all the types of true Insectivora and with the Opossums.

This last comparison leads us, perhaps, towards the origin of the Insectivora. In the East, the Bangsrings, and notably the beautiful little Ptilocerque, and the curious genusHylomys, which, again, seems to unite the Bangsrings with the Hedgehogs through the anomalous genusGymnura, present manifest relationships with the Phalangers, some of which abound in the islands further to the east. From these animals to the true Shrews, many of which abound in the east, is no great step. On the other hand, we have already seen that Brandt recognised Opossum-like characters in hisSolenodon, but it must be confessed that these are almost exclusively external. Professor Leidy describes, besidesOmomysabove referred to, some other fossils from the Eocene of Wyoming, which he seems to regard as Insectivorous in habit, but Marsupial in structure; and the Stonesfield Mammals, although plainly Marsupial, have Insectivorous tendencies, so that the derivation of the type Insectivora from the Marsupials, or at all events the near affinity of the two orders, perhaps at several points of contact, may be looked upon as established.

In the other direction the affinities of the order would seem to be through the Shrews, Hedgehogs, and Centetidæ with the Carnivora, towards which also the curious West AfricanPotamogaleseems clearly to point. The Bangsrings, again, show some traces of an affinity to the Lemurs; andGaleopithecusseems almost to constitute a central point of alliances, uniting the Insectivora with the Lemurs and Bats, and further exhibiting, as Mr. Wallace thinks, certain peculiarities which smackstrongly of direct Marsupial relations. The relationship of the Insectivora to the Rodentia can hardly be regarded as a true affinity, although the analogies between different types in the two orders are among the most striking phenomena of the kind with which we are acquainted. The type of the Mice and Rats is reproduced by the Shrews, the Squirrels by the Bangsrings, the Porcupines by the Hedgehogs and Tanrecs, the Jerboas by the Jumping Shrews, and the Ondatra by the Desmans; whilst even the highly specialised Moles are reflected among the Rodents by the various species of Mole-Rats. But none of these resemblances indicate affinity, and the Rodent type may be regarded as differentiated from the old probably Marsupial ancestral forms quite independently of the Insectivora.

W. S. DALLAS.

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