George Herbert Carpenter

“ These workers then take on themselves the labour of the colony, some collecting food, which they transfer to their comrades within the nest whose duty is to tend and feed the larvae. The foundress-queen is now waited on by the workers, who supply her with food and spare her all cares of work, so that henceforth she may devote her whole energies to egg-laying. The population of the colony increases fast, and a well-grown nest contains several “queens” and males, besides a large number of workers. ”

“ The development of such diversely-formed insects as the offspring of the unmodified females which show none of their peculiarities raises many points of difficulty for students in heredity. It is thought that the differences are, in part at least, due to differences in the nature of the food supplied to larvae, which are apparently all alike. But the ovaries of worker ants are in some cases sufficiently developed for the production of eggs, which may give rise parthenogenetically to male, queen or worker offspring. ”

“ Further, while among wasps and bees we find some solitary and some social genera, the ants as a family are social, though some aberrant species are dependent on the workers of other ants. It is interesting and suggestive that in a few families of digging Hymenoptera (such as the Mutillidae) , allied to the ants, the females are wingless. The perfect female or “queen” ants (figs. 1, 1, 3, a) often cast their wings (fig. 3, b) after the nuptial flight; in a few species the females, and in still fewer the males, never develop wings. ”

“ Springtails and bristle-tails live in damp concealed places—under stones or tree-bark, in moss, and in the decaying vegetable or animal matter which serves as food for most of them. Some species, however, eat fresh plant-tissues. A species of bristle-tail (Machilis maritima) and quite a number of springtails haunt the sea-coast at or below high-water mark. In such localities many thousands of individuals may sometimes be found associated together. The insect fauna of limestone caves both in Europe and North America is largely composed of Aptera, especially Collembola. ”

“ Ants invite one another to work, or ask for food from one another, by means of pats with the feelers; and they respond to the solicitations of their guest—beetles or mites, who ask for food by patting the ants with their feet. In all probability the actions of ants are for the most part instinctive or reflex, and some observers, such as A. Bethe, deny them all claim to psychical qualities. But it seems impossible to doubt that in many cases ants behave in a manner that must be considered intelligent, that they can learn by experience and that they possess memory. ”

“ In such cases the absence of wings must be regarded as secondary—due to a parasitic or other special manner of life. But the bristle-tails and springtails, which form the modern order Aptera, are all without any trace of wings, and, on account of several remarkable archaic characters which they exhibit, there is reason for believing that they are primitively wingless—that they represent an early offshoot which sprang from the ancestral stock of the Hexapoda before organs of flight had been acquired by the class. ”

“ The fact that the name of the ant has come down in English from a thousand years ago shows that this class of insects impressed the old inhabitants of England as they impressed the Hebrews and Greeks. ”

“ In these ants the difference between the large, heavy, winged males and females, and the small, long-legged, active workers, is so great, that various forms of the same species have been often referred to distinct genera; in Eciton, for example, the female has a single petiolate abdominal segment, the worker two. The workers of these ants range over the country in large armies, killing and carrying off all the insects and spiders that they find and sometimes attacking vertebrates. ”

“ Lubbock goes so far as to conclude the account of his experiments with the remark that “It is difficult altogether to deny them the gift of reason ... their mental powers differ from those of men, not so much in kind as in degree.” ”

“ On patting their carrier or some passing ant, the mites are supplied with food, no service being rendered by them in return for the ants’ care. Perhaps the ants derive from these seemingly useless guests the same satisfaction as we obtain by keeping pet animals. Recent advance in our knowledge of the guests and associates of ants is due principally to E. Wasmann, who has compiled a list of nearly 1500 species of insects, arachnids and crustaceans, inhabiting ants’ nests. ”

“ The warmth, shelter and abundant food in the nests, due both to the fresh supplies brought in by the ants and to the large amount of waste matter that accumulates, must prove strongly attractive to the various “guests.” Some of the inmates of ants’ nests are here for the purpose of preying upon the ants or their larvae, so that we find all kinds of relations between the owners of the nests and their companions, from mutual benefit to active hostility. ”

“ There are several forms of worker in these species, some with enormous heads, which remain in the underground nests, while their smaller comrades scour the country in search of suitable trees, which they ascend, biting off small circular pieces from the leaves, and carrying them off to the nests. Their labour often results in the complete defoliation of the tree. The tracks along which the ants carry the leaves to their nests are often in part subterranean. ”

“ The hinder abdominal segments and the stings of the queens and workers resemble those of other stinging Hymenoptera. But there are several subfamilies of ants whose females have the lancets of the sting useless for piercing, although the poison-glands are functional, their secretion being ejected by the insect, when occasion may arise, from the greatly enlarged reservoir, the reduced sting acting as a squirt.
Nests.—The nests of different kinds of ants are constructed in very different situations; many species (Lasius, for example) make underground nests ”

“ Lubbock’s experiments of inducing ants to seek objects that had been removed show that they are guided by scent rather than by sight, and that any disturbance of their surroundings often causes great uncertainty in their actions. ”

“ The brain is well developed and its “mushroom-bodies” are exceptionally large. The mandibles, which are frequently used for carrying various objects, are situated well to the outside of the maxillae, so that they can be opened and shut without interfering with the latter. The peculiar form and arrangement of the anterior abdominal segments have already been described. The fourth abdominal segment is often very large, and forms the greater part of the hind-body ”

“ Distribution and Habits.—The Aptera are probably the most widely distributed of all insects. Among the bristle-tails we find the genus Machilis, represented in Europe (including the Faeroe Islands) and in Chile; while Campodea lives high on the mountains and in the deepest caves. The springtails have even a wider distribution. The genus Isotoma, for example, has some of its numerous species in regions so remote as Alaska, Franz Josef Land, the Sandwich Islands, the South Orkneys, Graham Land, Kerguelen and South Victoria Land. ”

“ In the Entomobryidae the body is elongate and clearly segmented, but the dorsal region (tergum) of the prothorax is much reduced and the head downwardly directed; the spring is well developed. In the Achorutidae the head is forwardly directed, the tergum of the prothorax conspicuous, and the spring small or vestigial. ”

“ The workers in question remain within the nest, suspended by their feet, and serve as living honey-pots for the colony, becoming so distended by the supplies of honey poured into their mouths by their foraging comrades that their abdomens become sub-globular, the pale intersegmental membrane being tightly stretched between the widely-separated dark sclerites. ”