Adam Sedgwick

“ Mallock has described many beautiful scenes in his book, but I think he could have found few more beautiful than this old garden with its deserted gardener's house, now a heap of ruins, but overgrown with masses of luxuriant vegetation, with beautiful flowers peeping out here and there as if charitably endeavouring to hide the negligence of man, and to turn the desolation into a scene of beauty. ”

“ It is rare to find the post-embryonic development of an Insect occupying so long a period, so that we are justified in saying that brief as may be the life of the may-fly itself, the period of preparation for it is longer than usual. Réaumur says, speaking of the winged fly, that its life is so short that some species never see the sun. Their emergence from the nymph-skin taking place at sunset, the duties of the generation have been, so far as these individuals are concerned, completed before the morning, and they die before sunrise. ”

“ The structure of the outer skeleton, or external part of the body, exhibits some peculiarities, the chief of which is the detachment of the side-pieces of the prothorax and their great development. Not less remarkable is the abstraction of a segment from the abdomen to become, as it were, part of the thorax; while between the first and second true segments of the abdomen there exists a joint, or articulation, of the utmost mechanical perfection, enabling the operations of stinging and piercing to be executed with an accuracy that cannot be surpassed. ”

“ A very simple calculation will show how favourable some of the chief features of Insect life are. Let it be supposed that growth of the individual takes time in proportion to the bulk attained, and let A be an animal that weighs one ounce, B a creature that weighs ten ounces, each having the power of producing 100 young when full grown; a simple calculation shows that after the lapse of a time necessary for the production of one generation of the larger creature the produce of the smaller animal will enormously outweigh that of its bulkier rival. ”

“ Astonishing as may be the rapidity of the physiological processes of Insects, the results attained by them are, it must be admitted, scarcely less admirable: the structures of the Insect's body exhibit a perfection that, from a mechanical point of view, is unsurpassed, while the external beauty of some of the creatures makes them fit associates of the most delicate flowers or no mean rivals of the most gorgeous of the feathered world. The words {85}of Linnaeus, "Natura in minimis maxime miranda," are not a mere rhetorical effort, but the expression of a simple truth. ”

“ Termitidae belong to the division of Insects in which the wings are developed outside the body; Hymenoptera to the division in which they are developed inside the body. In Termites the growth of the individual is slow, and the final form is reached gradually. In the ants the growth is carried on with great rapidity, and during it the Insect is a helpless maggot absolutely dependent on the attentions of its seniors, while the difference in form and structure between the ant-larva and the ant are enormous. Both anatomy and ontogeny are profoundly different in ants and Termites. ”

“ Why does the larva grow up to a certain period with great rapidity, then cease its appropriating power and break up the parts that have been so rapidly and recently formed? And why do the imaginal buds remain quiescent till the other tissues are being disintegrated, and then, instead of sharing the general condition of disintegration, commence a career of development? ”

“ One of the most remarkable of the features of Orthoptera is that a great difference frequently exists between the colours of the tegmina and of the wings, i.e. the front and hind wings; the latter are concealed in the condition of repose, but when activity is entered on and they are displayed, the individual becomes in appearance a totally different creature. In some cases, contrary to what usually occurs in Insects, it is the female that is most remarkable; the male in Mantidae and Phasmidae being frequently a creature of quite inferior appearance and power in comparison with his consort. ”

“ It is for the same reason improbable that a fluid injected by the parent fly determines the gall's growth. It is true that the parent fly does exude a liquid during the act of oviposition, but this is believed to be merely of a lubricant nature, and not to influence the development. It is said that the gall begins to form in some cases before the larva is actually hatched, but the eggs of some Hymenoptera exhibit remarkable phenomena of growth, so that the egg, even during development of the embryo in it, may in these cases, exert an influence on the meristem. ”

“ As the number of segments in the adult Insect corresponds—except in the head—with the number of divisions that appear very early in the embryo, we conclude that the segmentation of the adult is, even in Insects which change their form very greatly during growth, due to the condition that existed in the embryo; but it must not be forgotten that important secondary changes occur in the somites during the growth and development of the individual. ”

“ If a male Lithobius sees the egg he makes a rush at the female, seizes the egg, and at once devours it. All the subsequent proceedings of the female seem to be directed to the frustration of this act of cannibalism. As soon as the egg is firmly clasped in the little hooks she rushes off to a convenient place away from the male, and uses her hooks to roll the egg round and round until it is completely covered by earth, which sticks to it owing to the viscous material with which it is coated; she also employs her hind legs, which have glands on the thighs, to effect her purpose. ”

“ The dragon-flies form a very natural and distinct group of Insects. All the species are recognised with ease as belonging to the family. They are invariably provided with wings in the perfect state, and many of them are amongst the most active of Insects. Their anatomy is, in several respects, very remarkable.
The head is large and is concave behind; it is attached to the thorax in such a way that it rotates on two cervical sclerites that project forwards, and in some cases almost meet in a point in front; hence it possesses extreme mobility, the power of rotation being very great. ”

“ The musical powers of the saltatorial Orthoptera are, however, specially characteristic of the male sex. There is evidence that these powers are of great importance to the creatures, though in what way is far from clear. Some parts of the structures of the body are in many of these musical species clearly dominated by the musical organs, and are apparently specially directed to securing their efficiency. We find in some Locustidae that the tegmina are nothing but sound-producing instruments, while the pronotum is prolonged to form a hood that protects them without encumbering their action. ”

“ Some Insects get quit of a considerable quantity of matter by their ecdyses, while in others the amount is comparatively slight. It has been thought that the moulting is effected in order to permit of increase of size of the Insect, but there are facts which point to the conclusion that this is only a factor of secondary importance in the matter. One of these is that many Insects make their first ecdysis almost immediately after they leave the egg; this is the case with the young larva of the blowfly, which, according to Lowne, moults within two hours of its emergence from the egg. ”

“ Fig-Insects are apparently more numerous in South America than they are in any other part of the world; and Fritz-Müller has discovered [465] a number of species there of a very extraordinary character, several of them possessing two forms of the male, one winged like the female, the other wingless and so different in character that they were considered to belong to a different genus. The wingless male of a species found in Madagascar, Kradibia cowani, has the peculiarity of possessing only four legs, the middle pair being represented merely by minute two-jointed rudiments. ”

“ In the social Hymenoptera it has been ascertained that the so-called neuters (which in these Insects are always females) can, and occasionally do, produce young, but in the case of the Termites it has never been suggested that the sexual organs of the workers and soldiers, whether male or female, ever become fruitful; moreover, the phenomena of the production of young by the white ants are of such a nature as to render it in the highest degree improbable that either workers or soldiers ever take any direct part in it. ”

“ It should be remarked that the phenomena connected with the social life of Insects are still only very imperfectly known; many highly important points being quite obscure, and our ideas being too much based on fragments gathered from the lives of different species. The honey bee is the only social Insect of whose economy we have anything approaching to a wide knowledge, and even in the case of this Insect our information is neither so complete nor so precise as is desirable. ”

“ Swarms consisting of millions of individuals are occasionally witnessed. D'Albertis observed Palingenia papuana in countless myriads on the Fly River in New Guinea: "For miles the surface of the river, from side to side, was white with them as they hung over it on gauzy wings; at certain moments, obeying some mysterious signal, they would rise in the air, and then sink down anew like a fall of snow." He further states that the two sexes were in very disproportionate numbers, and estimates that there was but a single female to every five or six thousand males. ”

“ The larvae of the Encyrtus are at first entirely confined to this sac, but when they have consumed all the nutritive matter in it, they leave it and pass the remainder of their larval and pupal existence in the body-cavity of the caterpillar. They live at first on the lymph (blood) of the Insect, and apparently do it no harm; nevertheless the strength of the caterpillar is so much enfeebled that it fails to undergo the transformation to a pupa; the parasites then devour its interior, and use the empty skin as a nidus for their own pupation ”

“ Burying its abdomen in the surface of the earth, the Insect collects on to its head, by means of the front leg, the sand from the side which is nearest to the centre, and then jerks the sand to a distance. By making a second circuit within the first one, and then another, the soil is gradually removed, and a conical pit is formed, at the bottom of which the ant-lion lurks, burying its body but leaving its formidable mandibles widely extended and projecting from the sand. In this position the young ant-lion waits patiently till some wandering Insect trespasses on its domains. ”

“ This phenomenon is usually limited to a small number of generations, as in the case of the Aphididae, or even to a single generation, as occurs in the alternation of generations of many Cynipidae, a parthenogenetic alternating with a sexual generation. There are, however, a few species of Insects of which no male is known (in Tenthredinidae, Cynipidae, Coccidae) , and these must be looked on as perpetually parthenogenetic. It is a curious fact that the result of parthenogenesis in some species is the production of only one sex, which in some Insects is female, in others male ”

“ The physiological problems connected with Insect parasitism are of great interest to the entomologist; the modes of nutrition and respiration of these encaged creatures could not fail to be most instructive were we fully acquainted with them. It is obvious that when an Insect-egg is laid inside another Insect's egg, and the parasite has to undergo the whole of its growth therein, it is in the strangest condition as regards nutrition. It is unnecessary for the intruded egg to have yolk of its own ”

“ The common cricket of our houses, Gryllus (Acheta) domesticus (Fig. 204) , has a very wide distribution in the Old World, and is also found in North America. It is believed to have had its natural distribution extended by commerce, though really nothing is known as to its original habitat. The shrill chirping of this little Insect is frequently heard at night in houses, even in the most densely inhabited parts of great cities. Neither the female nor the young are musical, yet the chirping may be heard at all seasons of the year, as young and adults coexist independent of season. ”

“ The popular name appears to be due to the fact that ants—Formica in Latin, Fourmi in French—form a large part of the victims; while lion—the other part of the name—is doubtless due to its prowess as a destroyer of animal life, though, as Réaumur long ago remarked, it is a mistake to apply the term lion to an Insect that captures its prey by strategy and by snares rather than by rapidity and strength. The imago of Myrmeleon is of shy disposition, and is rarely seen even in localities where the larva is abundant. It is of nocturnal habits, and is considered by Dufour to be carnivorous. ”