Fig. 30.—The Pupa of the Privet Hawk (Ligustri).
Fig. 31.—The Chrysalis of the Large White Butterfly (Brassicæ).
The newly exposed skin of the chrysalis is very soft and moist, but as it hardens it forms a membranous or horny covering that protects and holds firmly in place the trunk and the various limbs and appendages that are distinctly to be traced on the under surface.
If, however, you examine a chrysalis directly after the moult is over, you will often find that the wings, antennæ, proboscis, and legs of the future butterfly can be easily separated from the trunk of the body on which they lie by means of a blunt needle, and can be spread out so as to be quite free from that surface.
In form the chrysalides of butterflies and moths are as variable as the caterpillars. Many of the former are sharply angular like that of the 'Small Tortoiseshell' already mentioned; but some of the butterflies—the Skippers (page 197)—have smooth and tapering chrysalides, and so have most of the moths.
In colour they are equally variable. Some are beautifully tinted with delicate shades of green, some spotted on a light ground, some striped with bands more or less gaudy and distinct, but the prevailing tint, especially among the moths, is a reddish brown, often so deep that it is almost a black.
Fig. 32.—The Pupa of the Dark Green Fritillary (Aglaia).
Fig. 33.—The Pupa of the Black-veined White Butterfly (Cratægi).
As a rule there is no marked resemblance between the different stages of the same insect. Thus, a brilliantly coloured caterpillar may change to a dull and unattractive chrysalis, from which may emerge a butterfly or moth that partakes of the colours of neither. But in a few cases therearecolours or other features that remain persistent throughout the three stages, or show themselves prominently in two.
An interesting example in point is that of the Magpie or Currant Moth (page 279). The caterpillar of this moth is cream-coloured, with orange stripes along the sides, and very bold black markings down the back. The chrysalis, which is at first entirely yellow, afterwards turns black with the exception of some yellow transverse bands. Then, the moth exhibits the same colours as these two earlier stages, with the same degree of boldness; for its pale cream-coloured wings, tinted with patches of yellow, are marked with numerous deep black spots. Thus, in this case, we find the same general character of the colouring throughout the insect's existence.
Fig. 34.—The Pupa of the Currant Moth.
Fig. 35.—Pupa of the Pale Tussock Moth (Pudibunda).
Another interesting example, though not so striking as the last, is to be found in the case of a group of moths known as theLiparidæ. The caterpillars of these are remarkable for their very hairy bodies, often ornamentedby several bold brush-like tufts. The chrysalides are also hairy; and several of the moths themselves are not only thickly clad with shaggy hair, but a bold tuft often tips the abdomen.
We must not leave these few remarks on the characters of chrysalides without a mention of the brilliant spots of burnished gold that decorate the pupæ of certain butterflies. This is the feature that led to the invention of the termchrysalis, which is derived from the Greek wordchrysos, meaninggold. For the same reason the termaureliahas been applied to the pupæ ofLepidoptera, this being derived fromaurum—the Latin name for gold.
Strictly, then, these two terms apply only to the pupæ of a certain number of the butterflies; but the former is now generally used to designate the pupæ of all theLepidoptera, and is even extended to the corresponding stages of insects of other orders.
If you examine one of these gold-speckled chrysalides, the brilliant metallic lustre seems to belong to the outer surface, just as if certain spots had been tipped with real gold; but after the butterfly has quitted its case the beautiful golden spots are gone. This proves that the metallic appearance is not due to reflection from the outer surface of the chrysalis, but to a reflection from some structure beneath it. This latter is a very thin membrane which lies just under the outer transparent covering of the chrysalis.
The period during which theLepidopteraremain in the chrysalis state varies very considerably in different species, and also depends more or less on the temperature. As a rule, when a caterpillar pupates before the end of the summer, it remains dormant in the pupal condition for only a few weeks; but, if late in the summer or in the autumn, it remains in this condition throughout the winter, and emerges in the following spring or early summer.
Both these conditions are illustrated in the life history of the Large White or Cabbage Butterfly—an insect with which we have already become acquainted. We get two distinct broods of this butterfly every year, the first appearing in May and the second in August. The eggs of the first brood hatch in about a fortnight, and the larvæ are full grown about four weeks later. These then change to chrysalides, from which the perfect insects (the second brood) emerge in a few weeks—the period varying slightly with the temperature of the season. From the eggs of this second brood we get another invading army of cabbage eaters that change to pupæ late in the summer. These remain dormant till the followingApril, and may be found in numbers throughout the winter, attached to the walls and fences of kitchen and market gardens.
If, then, the pupæ of the same species are so influenced by the temperatures of the seasons, can we limit or prolong the period of quiescence by subjecting them to high or low temperatures artificially produced? Most certainly we can; and every practical entomologist knows how to obtain the perfect butterflies and moths of certain species long before their appointed times, or, if he desires it, to compel them to remain in their dormant stage long after the natural period has terminated.
Sometimes an enthusiastic insect hunter obtains a large number of what we may term 'winter pupæ,' by collecting and breeding various species. He also anticipates a number of successful captures of perfect insects during the following summer. Thus, from two distinct sources, he obtains a goodly assortment of butterflies and moths, the setting, preserving, and arranging of which entails an immense amount of home work.
Under such circumstances he will sometimes endeavour to cause some of his pupæ to emerge before their accustomed time, so that he may get some of his insects 'on the boards' before his field work is in full swing, and so avoid a rush, or prevent the loss of insects that will be spoiled before he has time to take them in hand.
This process of hurrying up his pupæ he calls 'forcing,' and simply consists in keeping them for a time in a warm room or hothouse where the high temperature is pretty constant.
On the other hand, the entomologist may desire to try the effect of a continuedlowtemperature on his pupæ. This he can do by placing his pupæ in an ice house. Such experiments have often been performed, and the results are very interesting. In some cases the emergence of the perfect insect has been delayed for many months, and even years; and then, after an exposure to a normal temperature lasting only a week or two, the winged insect has made its appearance just as if nothing unusual had happened.
Such are the effects ofextremetemperatures on the duration of the chrysalis state; and we naturally infer, from such results, that the pupa under natural conditions is influenced, though in a lesser degree, by the variations experienced with the seasons, especially in such a fickle climate as our own.
The insect hunter has always to bear this in mind, and particularly so when he sets out on a search for certain desired species. Suppose, for example, he has set his mind on the capture of acertain butterfly thatusuallyappears in thefirstweek in May. Before finally naming the day, he has to consider what the weather has been during the last few weeks, and if he finds that this has been much warmer than the average for the corresponding periods in the past, he selects a day inApril, earlier or later according to the difference between the present season and the average.
If he does not pay due attention to such considerations, he will sometimes find that all the insects netted are shabby and much worn, even though, under average conditions, he would be catching newly emerged and brilliant specimens. This, then, will explain how it is that we so often see in entomologists' periodicals startling accounts of 'early captures,' and of the appearance of certain insects late in the season thatoughtnot to have emerged till the following summer.
I will give just one illustration of these variations. The beautiful Orange Tip Butterfly (Plate I, fig. 7) generally appears about the middle of May in the southern counties. Farther north it is of course a little later. In the north of England it has been taken in June; and in Scotland as late as July. On the other hand, I have taken it in Gloucestershire as early as March, on a rather bleak day with a cold east wind; and, withal, in a field on the slope of the Cotswolds fully exposed to the unfavourable breeze; but it was evident that, in this case, the butterfly had been enticed from its winter quarters by the milder weather of the few previous weeks.
It may be as well, in passing, to observe that it is not only the pupa that is influenced by temperature. The hatching of eggs may be forced by high temperatures, or be retarded by exposure to cold; and in nature the period of incubation varies with the seasons. The larvæ, too, grow faster or more slowly, or pupate earlier or later from similar causes. And so no very definite date or period can be assigned to any one stage of any insect.
Now let us return to one of the chrysalides that we have already watched through the earlier stages of its existence, and follow it in its future development.
It is now, as we say, in its quiescent or dormant condition, but we must not suppose that it is always in a profound sleep, nor can we say that it is insensible to its surroundings. Touch it gently or surprise it with a puff of air from your mouth, and it will begin to wag its pointed tail, sometimes with such vigour as to send the body rolling round and round in its box. Lay it on a bed of cocoa-nutfibre or finely sifted soil and let it remainquite undisturbedfor a few hours or days, and you will probably find that, by occasional movements of its body, it has made a slight depression in its bed, and lies partly submerged. I have known some chrysalides to completely bury themselves in this way during the course of a day or two, and others to partly expose themselves after having been lightly covered. Others again, I have observed, will move smartly if a strong light is suddenly turned on them. Many, too, certainly appear to have a strong objection to exposure to the direct rays of a hot sun; for, when thus exposed, they will struggle persistently, as if to work their bodies into some shady corner. I would not advise a young entomologist to try this experiment, however, if he values the pupæ he possesses, for direct sunlight is undoubtedly very harmful to many species, and perhaps it is to all.
Some chrysalides are not nearly so active as has just been represented; in fact, there are many which seem to show no signs of life during the greater part of the time spent in that state. But in all, whether apparently active or not, certain important internal changes are at work. We have already noticed that, even in the last days of thelarvalexistence, some of the organs of the future imago are to be traced. But these are as yet imperfectly developed. We have also observed that a continuation of these changes, gradually carried on, would be impossible in a voracious feeder; so the insect, now fully grown, and no longer requiring a supply of food, settles down in perfect quiet, submitting itself quite passively to any further changes that nature may demand.
It has already suffered the loss of its claspers. Its wonderful jaws that did so much damage (for good or evil as the case may be) to the vegetable world are now gone, and the bulky digestive apparatus has rapidly dwindled to useless dimensions. These and other changes, already in progress, have to be perfected while the creature is in a restful and helpless condition, though they may often be retarded or even suspended during cold weather when progress would certainly bring it to an untimely end.
But now the grandest of all these transformation scenes is nigh at hand. The protective skin is already loosening from the almost perfect imago, and consequently feels softer and far more yielding than it did when in close contact with the body: the swaddled butterfly or moth (for such the pupa is) is slowly preparing to throw off its imprisoning garb. The wings and largecompound eyes are assuming their final colours, which now begin to show themselves through the more or less transparent skin, and the long legs, the perfectly formed antennæ, and the slender proboscis, all of which are folded closely under the creature's thorax, now begin to move within their loosened sheaths.
Now let us watch it closely, for one of the most wonderful sights ever witnessed by a naturalist is about to be presented to our view. We think we can observe slight movements; and, it may be, we can actually see the struggling insect endeavouring to set itself free. The legs and proboscis are moving within the loosened skin; and lo! as we watch these motions, the prison wall bursts with a slight snapping noise (at least, such is the case with some of the larger species), and in a moment out pop a few long legs which immediately struggle for a foothold. The proboscis also appears, alternately lengthening itself out and coiling into a spiral, as if impatient to reach the sweet nectar from the bottom of some fragrant flower cup.
Fig. 36—A Butterfly, just after Emerging.
All this takes place in less time than one requires to describe it; and, before many seconds have passed, the struggling insect has quite completed its last moult, and is bidding good-bye to the rent garment that has done it good service for so long a time.
But how dreadfully disappointing! Did we not say only a few minutes since, that a beautiful butterfly or moth was about to emerge? How, then, is this? Here is an odd-looking creature, such as we have never seen before! True, it has the right kind of body, though even that is so soft and heavy that it is fairly dragged along as the insect walks. Its antennæ, too, seem to be just the right thing—that is, just what we were expecting to see. But oh! the wings! Are we looking at a deformity?—a failure on the part of Nature to produce what she ought?
We will not judge hastily, but continue to watch it a little longer. It seems very restless at first, and, with the fluttering apologies for wings, drags its heavy body along till it reaches some surface up which it can climb. If nothing of the kind is close at hand you may place aroughupright stick in its path, and it will immediately begin to ascend. Its motto is now 'Excelsior!' and its ambition to rise may be so great that, on reaching the very top of the stick provided for it, it struggles for a still higher positionin life till, failing to get a foothold in the air itself, it falls to the ground and has to retrace its steps.
I once thought I would like to test the perseverance of a large moth in performing its first upward journey; and as it was one from a chrysalis to be found in nature at the foot of a tree that attains some considerable height, I was, of course, prepared to exercise a little patience myself.
As soon as the moth had emerged, I placed it at the bottom of a window curtain that hung from about eight feet high to the floor. In less than half a minute it had reached the top, and was struggling hard to get still higher. I took it down, and again placed it at the bottom. Up it went as fast as before; and this was repeated nine times with exactly the same result. For the tenth time I placed the persevering creature at the bottom of the curtain; and, after it had walked about halfway up, itsuddenlystopped, apparently quite satisfied with having travelled a distance of over seventy feet in an upward direction. Its six legs were immediately arranged symmetrically in a business-like manner, and there it settled quite still, as if it had some definite object in stopping just exactly in that spot.
But we must now return to our own insect, which has by this time settled itself in a similar manner on the stick we provided for it. The peculiar organs which represent the wings, though so very small, show distinctly, in miniature, the colour and pattern of the fully developed wings of the species. An interesting change is just now commencing. These wings are apparently growing larger, but the development is very unequal, so that they become curled and crumpled till they are even more unsightly than before. All seems to be going amiss. But this lasts only for a short time. The fluid from the body steadily rushes into thenervures, causing the wings to expand, and in a few minutes the beautiful pinions are stretched to the full extent, assume their normal shape, and expose the full glory of their brilliant colours.
It may be interesting if I give an example showing the exact time taken for the full development of the wings of a certain insect. So I will here quote an entry from my note book; and, by the way, let me strongly advise all my young readers who follow up this subject to habitually enter in a book kept specially for the purpose all facts which strike them as they pursue their study of nature. The note to which I refer runs as follows:
'Early on the evening of the 22nd [April] I selected a fewchrysalides of Populi [the Poplar Hawk Moth,page 209] which, from the looseness of their cases, were thought to be just on the point of emerging. At 8.46 one of them showed signs of restlessness; and, after a few vigorous movements, during which it rolled itself over on the glass [I had placed the pupæ on a piece of plate glass so that slight movements might be more easily detected], the front of its case was suddenly thrust off with considerable force; and inless than four secondsthe imago was quite free and crawling on the table. After trying hard to reach a higher point than was provided for about four minutes, it rested to expand its wings—now about seven-sixteenths of an inch long, or one-third the total length of the body. At 9 o'clock the wings reached half the length of the body, and were much curled. At 9.12 they were fully expanded and straightened out.'
From this extract we see that the whole period from the bursting of the case to the full expansion of the wings was only twenty-six minutes; and it will be well to remind the reader that the process occupies even a much shorter time than this with many species, both of butterflies and moths. It will be observed, also, that theeveningwas chosen as the time for the observation. There was a reason for this. The Poplar Hawk Moth, as is the case with many others, almost invariably emerges from the chrysalis in the evening—usually after dark. But it may be mentioned in passing that a far larger number of theLepidopteraas invariably emerge in the morning.
Again we will return to our newly emerged insect, for there are still one or two interesting points to observe. The wings have fully expanded, it is true, but how very limp they are! Take the creature on the tip of your finger and hold it so that its body is in a horizontal position. Immediately the wings bend downward with their own weight, so soft and flexible are they. The body, too, is still very soft, and apparently much too heavy for flight. Then, if you place it on a flat surface, it will immediately try to find some perpendicular or overhanging surface from which it can suspend itself by means of its legs, so that the pendant and straightened wings are in the best possible position for drying. As the insect walks away in search of such a resting place, the body still drags as it did before, and the wings bend over, either both on one side or one on each side of the body.
It is some time before the wings are sufficiently dry and rigid for flight, but the period varies greatly with different species.Some of the small butterflies and moths take to flight long before an hour has passed, but in many cases several hours elapse before the creature starts from its first resting place. Butterflies that emerge in the morning spend their first day actively on the wing; but the nocturnal moths that emerge early in the day do not fly till evening twilight. When, however, the time arrives, the insect flutters its wings as if to test their power before committing itself to the air; and frequently, after only a few seconds spent in this preparatory exercise, off it darts with astonishing rapidity. But others seem far more cautious. They vibrate their wings, sometimes with such rapidity that they are lost in a kind of mist, and with such power that their bodies would be carried suddenly into the air were they not firmly anchored by three pairs of hooked claws. Then, continuing the rapid vibration, they move slowly along, always holding on firmly by one or more legs, as if to still further satisfy themselves concerning the efficiency of their wings. Then they venture on a few short trial trips from one neighbouring object to another, and at last gain sufficient confidence for a long voyage.
How strange must be the feelings of a winged insect during its first flight! After a long period during which it was a helpless, crawling grub, and this followed by a term of imprisonment during which it was almost or quite shut off from the world, it now suddenly acquires such great powers of locomotion that it is often a match for ourselves.
But, alas! this life is short. A few days spent in sporting with those it meets and in sucking the sweet juices of many flowers; then a day or two during which the female deposits its eggs; again a few days employed in pleasures that become less and less attractive, till, at last, the creature becomes weary of life and settles down to die.
We have now traced the complete life history of theLepidopterafrom the egg to the perfect insect, avoiding descriptions that apply only to certain species as far as possible, excepting where such are useful as illustrations.
Only one thing more remains to be done before we start in real earnest with our practical work. We shall shortly be giving hints on the modes of capture, the 'setting' and the preservation of butterflies and moths. And in so doing we shall often have to observe important points in which our dealings with these two great divisions of the order will differ very materially. Hence wemust not consider ourselves ready to proceed with the practical portion of the entomologist's labours till we are perfectly satisfied that we know the main features that enable us to distinguish between the butterflies and the moths, and also know just a little concerning the subdivisions on each side.
This, then, shall form the subject of the next short chapter.
TheLepidopteraare divided into two very unequal groups, to which we have so frequently alluded as 'Butterflies' and 'Moths.' And, although these two terms are popularly applied in a fairly accurate manner, yet, strange to say, very few persons indeed have any definite knowledge of the differences that entomologists recognise between the two groups.
Every entomologist has his circle of sympathetic and, perhaps, even admiring friends. Consequently, many a little package is sent round to his abode 'with great care,' accompanied by a note or a message concerning the fine 'butterfly I have just caught, and thought you would like to add to your collection.'
The 'butterflies' that so frequently reach us through these channels nearly always turn out to bebrightly colouredmoths, and this naturally gives one the idea that the popular notion as to the classification of theLepidopterais based on colour or brilliancy of design, the term 'butterfly' being applied to the gayer species, and 'moth' to the more dingy members of the race.
There is really some shadow of a reason in this method of nomenclature, for butterfliesare usuallymore brightly clad than moths; but the scientific classification, at least as far as the main divisions and subdivisions are concerned, has nothing whatever to do with colour or design; and we must at once acquaint ourselves with the fact that therearevery dingy butterflies, and most beautiful and highly coloured moths.
How shall we account for the fact that the specimens so kindly sent us by our friends are generally moths? Is it because moths are more numerous and more frequently seen? They are certainly more numerous; for, while our butterflies do not number seventyspecies, the other division contains about two thousand. Yet, in spite of this fact, moths are not generally observed as much as butterflies, for the former are nearly all night-fliers, and the latteralwaysfly by day and rest by night.
Still our question remains unanswered. The reason is this. The captives sent us are seldom caught on the wing. Most of our grown-up friends, even though they admire our own pluck and general carelessness concerning the remarks of the spectators of our entomological antics, would not themselves like to be seen, hat in hand, chasing a butterfly; and the night-flying moths are, of course, less frequently observed. But they often, in the course of their daily employments, meet with a large moth fast asleep in some corner of a dwelling house, workshop, or outhouse. Such moths are easily caught while in the midst of their slumbers, and, as they often make no attempt to fly by day, are as easily transferred to a box suitable for transmission by messenger or by post.
In the above few remarks we have alluded to some features by which the two great groups of theLepidopteramay be distinguished; but we have already referred (page 5) to a far more important one in our description of the various forms of antennæ. All butterflies—at least allBritishbutterflies—have knobbed or clubbed antennæ, while the corresponding organs of all our moths terminate in a sharp point.
This distinction obtains in all BritishLepidoptera, and is so far regarded as the most important basis of classification that naturalists have derived from it the two Greek terms that are synonymous with our two popular names—butterflies and moths. The scientific name for the former group isRhopalocera—a term derived from two Greek words, one signifying a horn, and the other a club, and thus meaning 'club-horned.' The corresponding name for moths isHeterocera, derived from the same source, and meaning 'variously horned.'
But, although we find embodied in these two long and formidable names an unerring mark of distinction between British butterflies and moths, we must not neglect other less important facts which, though less distinctive, are not without interest.
Observe a butterfly at rest. Its wings are turned vertically over its back, and brought so closely together that they often touch. In this position the 'upper' surfaces of the 'upper' wings are completely hidden from view, and the 'under' surfaces areexposed on the two sides, except that those of the 'upper' pair are partly hidden by the other pair.
Now look at a moth under the same circumstances, and you will generally find the wings lying over its body, which is almost or completely hidden beneath them. As a rule the upper pair together form a triangular figure, and entirely cover the second pair; but in some cases a portion of each of the under wings extends beyond the margin of those above them, and in others the upper pair extend so far forward that nearly the whole of the under wings is exposed behind them.
Fig. 37.—A Butterfly at Rest (Large Copper).
Fig. 38.—A Moth at Rest (Gothic).
Again, the wings of butterflies are so rigid that they can never be folded; but you will observe that the under wings of moths are generally very thin, soft, and pliant, and are neatly pleated lengthwise when not in use.
Another feature deserving notice is a slight difference to be often observed in the form of the body. The butterfly, which generally has a slender body, has a distinct constriction or waist between the thorax and abdomen. This is not so apparent with moths, and especially with the thick-bodied species.
TheRhopaloceraor Butterflies are divided intoFamilies, each of which contains insects that possess certain features in common by which they may all be distinguished from the members of any other family.
The British species represent eight families. They are as follows:
1.Papilionidæ.—Containing only one British species—the beautiful Swallow-tail (Plate I, fig. 1).
2.Pieridæ.—Containing ten species. These are often known collectively as the 'Whites,' but include four butterflies that are distinguished by beautiful shades of yellow and orange.
3.Nymphalidæ.—This family contains seventeen insects, among them being several splendid species. It includes the Fritillaries and Vanessas.
4.Apaturidæ.—Of this we have only one representative—the Purple Emperor (Plate V, fig. 1).
5.Satyridæ.—Including the 'Browns' and 'Heaths,' and numbering eleven species.
6.Lycænidæ.—Including the Hairstreaks, 'Coppers,' and 'Blues,' in all seventeen species.
7.Erycinidæ.—Containing only the 'Duke of Burgundy.'
8.Hesperiidæ.—This family contains seven British butterflies commonly known as the 'Skippers.'
Although all the members of the same family resemble each other in certain points of structure, or in their habits, yet we can often find among them a smaller group differing from all the others in one or two minor particulars. Such smaller groups are calledGenera.
To make this all quite clear we will take an example.
The Brimstone Butterfly (Plate II, fig. 4) belongs to the second family—Pieridæ,allthe members of which are distinguished from those of the other families by the characteristics mentioned onpage 141.
But our Brimstone Butterfly possesses another very prominent feature in which it differs from all the other BritishPieridæ, and that is the conspicuous projecting angles of both fore and hind wings. Among the foreign species of the family we are considering there are several that possess these angles; but as there are no others among our own members, the 'Brimstone' is placed by itself in the list of BritishLepidopteraas the only member of the genusGonopteryxor 'angle-winged' butterflies.
Thus the full relationship of this butterfly to other insects may be shown in the following manner:
The Brimstone Butterfly.
Now, every butterfly has a Latin or Greek name in addition to that by which it is popularly known. I should have saidtwoLatin or Greek names. The first of these is always thegenericname, and the second is the one by which we denote the particular member orspeciesof that genus. Thus, the scientific name of the Brimstone Butterfly isGonopteryx Rhamni.
'But,' the reader may be inclined to ask, 'why should we not be satisfied with the one popular name only?' And, 'If wemusthave a separate scientific name, could we not find suitable terms among our English words to build up such a name—one that might express the principal characteristics of the insect, and also serve all the purposes of classification?'
Such questions sound very reasonable, and so they are. But the entomologist's answer is this. We ourselves may get on well without the help of the dead languages, but we have brother naturalists all over the world, speaking a great variety of different languages. We endeavour to help one another—to exchange notes and generally to assist one another in our labours; and this can be greatly facilitated if we all adopt the same system of nomenclature. The educated of most of the great nations generally know something of Latin and Greek, and consequently the adoption of these languages is generally acceptable to all.
This sounds well, but for my own part I believe that if we are to make any branch of natural history a popular study, especially with the young, we must to a certain extent avoid anything that may prove distasteful. There is no doubt whatever that many a youngster has been turned away from the pursuit of the study of nature by the formidable array of almost unpronounceable names that stretch nearly halfway across a page; and those who desire to make such a study pleasant to beginners should be very cautious with the use of these necessary evils. One would think, on glancing over some of the scientific manuals that are written 'especially for the young,' that the authors considered our own too mean a language for so exalted a purpose, for in such works we find all or nearly all the popular names by which the schoolboy knows certain creatures he has seen entirely omitted, and the description of a species appended to a long Latin term that conveys no idea whatever to the reader, who is studying the description of a well-known animal or plant and doesn't know it.
Our plan will be to give the popular names throughout, except in the case of those few species that are not so well known as tohave received one; but the scientific names will always be given as well for the benefit of those readers who would like to know them. And the short description of the method of classification just given will enable the more ambitious of my readers to thoroughly understand the table of British butterflies and moths toward the end of the book.
This table includesallthe British species of butterflies and of the larger moths; and the arrangement is such as to show clearly the divisions into sections, families, &c. It will therefore be of great value for reference, and as a guide for the arrangement of the specimens in the cabinet.
In the foregoing description of the method of classification butterflies only are mentioned; but the division and arrangement of moths is carried out in just the same manner except that the system is a little more complicated. The number of moths is so large in comparison, that we are able to select from them some very large groups the species of which possess features in common. These groups are termedtribes, and are again divided into families just like the butterflies. Thus the arrangement of moths includestribes,families,generaandspecies. We will take an example by way of illustration as we did before, and ask the reader to verify the same by comparison with our table:
Example.—The 'Common Tiger' (Plate X, fig. 3).
I have already said that the Latin and Greek names of butterflies and moths are not at all necessary to the young entomologist. It is quite possible to be well acquainted with the natural history of these creatures, and to derive all the pleasure and benefits that the study of them can afford without the knowledge of such names; but most entomologists go in for them, often to the entire exclusion of the popular English terms.
There are those who consider themselves (or would have us consider them) expert entomologists because they have the powerto vomit forth a long list of scientific names of butterflies and moths which (to them) have no meaning whatever; and it is astonishing that we meet with so many youngsters who can rattle away such terms, and, at the same time, are totally ignorant of the real nature of the creatures they name.
If you wish to be a naturalist in the true sense of the term, study yourspecimens, and take but little pains to commit their hard names to memory; and you will then find that the latter will gradually become your own property without any special effort on your part. Your continued reference to illustrated works and museum collections will bring them to you almost unconsciously, and you will generally find your entomological vocabulary extending as rapidly as your cabinet becomes filled.
Again, with regard to themeaningsof the scientific terms, don't trouble much about them. It unfortunately happens that in a very large number of cases these names are ill chosen, and do not in any way refer to the distinguishing characteristics of the species to which they are applied. You will observe, too, if you look at the table, that many insects havetwoscientific names applied to the species, one being placed in brackets after the other. In such cases both these names are in common use, having both been applied by independent authorities, and the insertion of the two will prove an assistance at times.
It is a common practice with entomologists, in their communications, to use only the second orspecificname of insects. Thus, they would speak of the Brimstone Butterfly asRhamni, and notGonopteryx Rhamni. Whenwritinga communication, however, they very commonly place in front of the specific name the initial letter of the first orgenericname. Thus the full title of the butterfly just mentioned would be abbreviated toG. Rhamni.
Having said so much concerning the principles of classification and nomenclature, we will pass on to the practical portion of the entomologist's work.
It is not at all surprising that entomology should prove such a fascinating study to the young, and more especially that portion which deals with the department we are now considering. Butterflies and moths are among the most beautiful and most interesting of living creatures. The study of their life history is enchanting, and the creatures themselves are of such a size as to be conveniently handled and preserved, and withal occupy so little space that anyone with only moderate accommodation may possess a fairly typical collection.
Compare the work of the entomologist with that of one whose hobby is the study of mammals. The latter has to deal with large and cumbersome objects, a collection of which requires an enormous amount of space; and, unless he has the time and means to travel in foreign countries, he cannot get together a good typical collection of specimens representing his particular branch, for the few British mammals contain no representatives of several of the orders into which the class is divided.
Entomology is undoubtedly,par excellence,thestudy for youngsters. It is equally suited to the studious and to those of an adventurous turn of mind. It leads its follower into the bright sunshine and the flowery meadows; and with body and mind pleasantly occupied, the joy of living is deeply felt. The necessary apparatus can be made by anyone. No dangerous gun is required, and there are no precipitous rocks to scale. When the autumn flowers fade the year's work of the entomologist is not done, for the arrangingof his cabinet and the demands of his living specimens keep him more or less actively engaged until the flowers of the following spring call both him and the insects he loves once more into the field. And so, season after season, and year after year, he finds himself engrossed in labours so fascinating that idleness—the curse of so many of our youths—is with him an impossibility.
I assume that the readers of this book have a desire to take up the study of one branch of entomology—that of butterflies and moths—in real earnest; that they intend not only toreadabout these interesting insects, but toknowthem. And there is only one way in which one may really get to know living creatures; that is by searching them out in their haunts, observing their growth and habits, and by an occasional close examination in order to become acquainted with their structure.
Hence I shall in this, the practical portion of the work, give such information as will assist the beginner in catching, preserving, rearing, breeding, and arranging the specimens that are to form his collection.
There was a time when we would try to capture a butterfly at rest on a flower by a quick sweep of the hand, or, more commonly, by a sharp downward stroke of the cap. We were led to this action by a mere childish love of sport, or by a desire to possess an insect simply because it was pretty. When we succeeded in securing our prize, we handled it somewhat carelessly, often passing it from one hand to the other, or boxing it in our closed and perspiring fist till our fingers were dusted with the pretty microscopic scales of the creature's wings, and the wings themselves, stripped of all their beautiful clothing, were merely transparent and veined membranes. Having thus carelessly but unintentionally deprived the creature of its greatest beauty, we set it free, often in such a damaged or exhausted condition that the poor thing could scarcely fly.
But our childish ideas and inclinations have vanished. Now we would rather watch the insect than catch it, for we find much pleasure and interest in its varied movements. And if for purposes of study we occasionally require to make one captive, we proceed in such a manner as to preserve its beauty unimpaired. The cap now gives place to a well-made and suitable net; and we are careful to provide ourselves with sufficient and proper accommodation for our captives.
It is probable that many of my readers are as yet unacquainted with the nature of an entomologist's requirements for field work, so we shall describe them, confining ourselves at first to those that are required for a butterfly hunt.
First and foremost comes the net. This essential portion of your equipment may be either purchased or constructed by yourself. Very little skill is required to enable you to do the former. Provided your pocket is well charged, you may start off at once to the dealer in naturalists' appliances, and treat yourself to a complete outfit. But even in this case a little advice may not be out of place. See that what you purchase is verystronglymade. You can get nicely finished nets constructed on the most convenient principles, made to fold and go in an ordinary coat pocket, but withweak joints. See that you have the most convenient form of net by all means, but do not go in for convenience and appearance at the expense of strength and durability. Nothing is more annoying than to find your net give way just when you are in the midst of a good day's sport.