True Tales of the Insects
own." This bald statement he gravely gives in more elaborate guise: "The Insect, when it has found its proper Tree of Nourishment, lays its eggs separately in the Buds of it, which hatch when the Buds begin to shoot; the Insect then is nourished by the Juices of the Tree, and grows together with the Leaves till all its Body is perfected; and at the Fall of the Leaf, drops from the Tree with the Leaves growing to its Body like Winofs, and then walks about; this is not common enough with us to be easily believed, and what I should not have ventured to mention in this place, if the Insects themselves were not to be met with in the curious Cabinets of our own Country. " What I account the most curious point belonging to this Relation is, That the Sap of any Tree should be so naturally adapted to maintain at once both Vegetable and Animal Life; and by that means to unite the Parts of two Beings, so distinct from one another as Plants and Animals, and circulate the same Juices equally in the Vessels of both.... That a Leaf of a Plant should so unite itself with an Insect as to make one distinct living Body is wonderful."
All one can say is, the remarkable appearance of the insects affords some excuse for the absurdities of this romantic story. Somewhat more than a century later, the eggs of one of these insects were introduced from India to Edinburq-h,
where they hatched, and the living insects were under the observation of the late Mr. Andrew Murray for nearly eighteen months in the Royal Botanic Garden. Strangers used to search in i s h P h y 1 -vain to distin- g u lium from the su r rou nd i nof leaves. Mr. Murray says of one: " For the greatest period of its life it so exactly resem-bled the leaf on which it fed, that ^' h e n visitors were shown it they usually, after looking care- fully over the plant for a mi- nute or two, declared that they could see no insect. It had then to be more minutely pointed out to them; and al- though seeing is notoriously said to be be- 1 i e V i ng, it looked so absolutely the same as the leaves among which it rested that this FiG. 17. Graeffea coccophagns test rarely satis- fied them, and nothing would convince them that there was a real live insect there but the test of touch. It had to be stirred up to make it move." The same was true of some specimens exhibited alive
in 1867, at the Jardin d’Acclimatation at Paris. They were placed on a growing bush, from which most of the leaves were stripped, that they might be more easily perceived. If a large placard had not announced the presence of the insects, no one would have recognized anything ex- traordinary; and as_ it was, many persons, after carefully exa- mining the case, went away without being aware of having seen but the vinced that anything bush, — con-the placard referred to something too minute sight. Even microscopic, for their those who were acquainted — Fic. $.—A Walking-Leaf (Piyvium With the aspect of SSR NAOD SUE walking-leaves had often a long search to discover what was in reality before their eyes.
6
Dislriluitioii.
Not the genus Phyllium alone is exotic, the whole family of Phasmidse is eminently tropical. About six hundred species of the family are the way, a number known—by small in comparison with that in many of the large families of Insecta—but only four or five are found in Europe, slender apterous green or brown kinds, measuring but two or three inches in length; and they are all restricted to the south, only one reaching as far north as Central France. They belong to the genus Bacillus, and while common enough in the female form, in comparison the males are extremely rare. In the temperate regions of America we find similar restriction.
In the warm portions of the globe Phasmidse are of almost universal distribution. Formerly India and the isles of the Indian Archipelago were regarded as constituting the metropolis of the group, but recent re-searches seem rather to point to Australia as the region where they are now most largely developed. A species of Podacanthus is so common, that it is rare in the summer-time in any part of Australia to find a gum-tree without a few feeding upon it; and occasionally the trees for miles will be denuded of their foliage by it. New Zealand has several species of Phasmidse, differing from the Australian forms, and all wingless. Of America it
may be remarked, that not only is it less rich in Phasmidse than the Oriental hemisphere, but the species there have a tendency more pronounced to remain apterous. Among what may be called wingless species of the Orient, more usually the rudiments of wings are apparent, or the wings are more or less developed, although of the briefest description. From these differences, and others, it follows that the genera of the different continents are in great part distinct. Not only is this the case, but the greater number of species are confined within somewhat narrow geographical limits. It is easy to understand how insects so little addicted even to walking do not spread rapidly, and that, seeing their absolute dependence on plants which serve at once as their abode and their nutriment, they are affected more strongly than others by the modifying influence of the places which they inhabit; whence it comes that each little region possesses its species.
Existence is possible to the Phasmidse only in verdant regions, where delicate nourishment is always to be had within reach. They could not live in a dry climate, and on a soil often deprived of vegetation, their limited powers of locomotion being an insurmountable obstacle to their travelling over great distances in search of food. These facts explain at once the rarity of phasmidae in tropical Africa, and the manner in which they pre-eminently affect the humid and verdant isles of the
tropics, and it is for those of the Indian Archipelago, as before mentioned, they show partiaHty. Even species with laro-e individuals seem to be able to continue their existence in comparatively small isles.
That Walking- Sticks come of a Remote Antiquity.
Few groups of insects are so specialized; and one would naturally expect these bizarre creatures to be the outcome of a long series of forms in a special line of development. Some insects, said to belong to the genera Phasma and Bacteria, have been found fossil in one or two fragments in amber, belonging to the early part of the tertiary period. No phasmid has been unearthed from the great formations of the mesozoic period, so that, with the exception of a single insect-fossil from the tertiary strata in North America which has been recently referred to this family, but probably in mistake, we know nothing of fossil walking-sticks older than the remains preserved in amber. It must be stated, however, that the upper coal-measures of Commentry, France, have suddenly revealed a considerable number of forms that may be connected with our living Phasmidse, a discovery carrying these Orthoptera back at once to the remote antiquity of paleozoic times. iVI. Brongniart describes two remarkable gigantic insects
from the carboniferous beds. Both he and Scudder have treated these fossils as forming a distinct family called Protophasmidse. So far as we know them, these early types differed from those of to-day by being invariably winged, and in that both pairs of wings were adapted for flight; the front pair—what we now call wing-covers, or not leathery and tegmina—being thickened, as now, serving as mere protective flaps to the closed hinder pair, but were as large and diaphanous as their posterior fellows: these ancient insects explain the origin of our living giants, being twenty-five to fifty centimetres long, and as much as seventy in spread of wing. To them have been referred, on inferential grounds, a whole group of detached wings found in carboniferous beds in Europe and America. The)- further differed from modern types in having the several parts of the thorax more nearly equal in length similar, in fact, to the condition while still in the egg of walking-sticks of to-day; thus illustrating once more, what many naturalists believe, that in the development of the individual we may trace, more or less completel)-, the ancestral development of the race.
The Phasmidce are a singularly isolated group; we discover no transition properly so called between this family and others. So far as appearance goes, they approach most closely the mantidse; their forms are sometimes very much alike; in several mantids
8o TRUE TALES OF THE INSECTS.
(Thespis, etc.) the body is even as slender and cylindrical as among Phasmidje. Yet there is no real affinity between them, essential differences distinguish these groups; differences relating to the modifications of nearly every part of the body, in connection with habits diametrically opposed. Still, one can hardly but say there is a sort of parallelism between them; the two families constituting, so to speak, two collateral series, the one representing the herbivorous, the other the carnivorous type of the same form.
SAL TA TORI A
CHAPTER V.
LOCUSTS AND GRASSHOPl'ERS (aCKIDIID/E).
Fig, 19.—A GrasshoiiiK-i {Trit.xalis J'/ianwiiis).
The reader will perceive, on referrint^ to the Contents, that the families of the Orthoptera are divided into two sections. He will observe that the Mantidce and Phasmidae, already considered, belong to the Cursoria, or Runners, their hind legs being but little different from the others. We come now to speak of two families pertaining to the Saltatorial group, each remarkable for their saltatory powers, due to the great development of the hind legs, which are more elongate than the others,
and have thick and powerful thighs. As compared with the Mantidai and Phasmidse, which are amongst the most distinct of any subdivisions of the Insecta, these famiHes are much more intimately allied. Technically, they are known as Acridiidse and Locustidee; but, unfortunately, there is a certain amount of confusion between the scientific and common names, the latter not corresponding in their application with the family limits. The names Grasshopper and Locust are almost synonymous. Not only in a popular sense, but even by scientists, the word "grasshopper" is applied at one time to the true locusts or to the various species that constitute the Acridiidse, and at another to species belonging to the Locustidai; " grasshopper," in fact, is a collective term used to include most of the species of two different families. Notwithstanding this difficulty in applying the popular name, the distinctions between the insects composing the families are readily recognized. Briefly stated, while the Locustidse are usually found on the grass, bushes, and trees, and have very long thread-like antennae, generally longer than the body, and the tarsi four-jointed; Acridiida^ includes those species which generally reside on the ground, they have antennse of less than thirty joints, never exceeding the body in length, and the feet or tarsi short, with three distinct joints. With the Acridiidse we commence our consideration of the Saltatoria.
This family contains the majority of the species, a very large number, varying considerably in form and character; it is the most numerous in species and individuals of any of the families of Orthoptera. The small grasshoppers which are common in our fields give a very good idea of their general appearance. Active little insects having a body laterally somewhat compressed, a large head, conspicuous eyes, the hind legs termed for leaping, the wings in repose deflexed and pressed to the sides, our native grasshoppers, however insignificant and unimportant, represent the family quite as truly as do its many more imposing, remarkable, and interesting species.