Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/109

noxious effect upon the ant-colony have been already mentioned. Thus carbolic acid and corrosive sublimate appear to affect the ant-colony as poisonous agents; and solutions of tobacco, lime, soot, and walnut leaves, with urine, are also stated to prove effectual in destroying them, although these latter are decidedly inferior to the two first-mentioned substances. Corrosive sublimate, indeed, appears to have a curious and even specific action upon these forms, in rendering them actually maniacal, to use a phrase which is applicable generally to the human subject alone. Under the influence even of external contact with this substance, the ants in Grenada during their ravages of last century, were observed to be singularly affected, and were seen even to attack each other with outrageous violence, an effect also corroborated of late years in Central America by Mr Belt, who saw the rabid ants collected into small balls biting one another, and seizing hold of each other in a most extraordinary fashion under the influence of the mercurial poison. The corrosive sublimate, it is stated, can be effectively used only in dry weather.

A brief description of the Termites, or white ants, may appropriately conclude the present article. These forms have already been stated to be entirely different from the familiar and true ants, and to belong to the Neuropterous insects, whereas the true ants are classed with the Hymenoptera. They resemble the true ants in living in highly organised social communities, and in being endowed with as high and as specialised instincts. But they differ from them, first, in the fact that they do not undergo a complete metamorphosis, that is, the Termite larvae and pupae resemble the perfect insect, and do not pass through the defined stages of change and development characteristic of the true ants, bees, and other insects. The young Termite, in fact, differs from the ordinary adult only in the nonpossession of eyes, and from the sexual forms in the nondevelopment of wings. The white ants inhabit the tropical regions of the world generally, but are found in the greatest abundance in tropical South America. Their nests form characteristic structures, rising sometimes to a height of 5 or 6 feet, and constructed of earthy particles worked into a mass as hard and durable as stone. Many species of Termites are known, but they resemble one another in essential structure and habits. As indicated by their popular name, they are of a whitish colour and are soft-bodied. The Termite community consists, as in the true ants, of males, females, and workers or neuters. In the true ants the latter are undeveloped females, whereas in the Termites the sex of the neuters is wholly undeterminable; and in addition the workers are invariably divided into two distinct classes: the " soldiers/ with largely-developed jaws, whose sole office is to defend the community; and the ordinary " workers," on whom devolves the entire labour of the nest. Both classes of neuters are blind; and from a close examination of the eggs, the distinctions, not only between males and females, but also between the soldiers and workers, may be easily seen. The difference in food, so powerful in the development of sex and characteristics in other insects, does not therefore operate in the case of the Termites. The entire white ant colony and species also exhibits a division into subordinate groups and classes, the recognition and characters of which are very difficult of determination. And on this, as well as upon other grounds, the organisation of the white ant community is generally to be regarded as of a higher type than that of the familiar and true ants.

Fig. 4.—White Ant (Termes bellicotus). Male.

Fig. 5.—White Ant (Termes bellicosus). Soldier.

The nest of the Termites is known as a termitarium, the essential internal arrangement of which consists of a large number and series of chambers, connected by galleries and passages. Entrance to the nest is afforded by con cealed roads and subterranean passages. A large hillock may be a compound termitarium, formed by and inhabited by different species; and certain kinds of Termites build their nests of smaller size, sometimes of the consistence of paper. Their structures may be attached to the branches of trees, or they may be entirely subterranean, or concealed under the bark or within the stems of trees. The latter species are those which destroy timber, furniture, and household objects.

Within this curious home an equally curious community is found to reside. The king and queen represent the sexual part of the community, the true neuters or workers form the greater part of the ordinary individuals, and the soldiers and winged Termites complete the list of inmates. The royal cells, tenanted by the king and queen, exist in the inmost part of the nest, and are closely guarded by a retinue of workers. The king and queen are wingless and much larger than the neuter ants. The queen Termite when within the royal cell is permanently gravid, the abdomen being immensely distended with eggs, which as they are produced, are seized upon by the workers, and conveyed to special cells prepared for their reception. The relations of the winged Termites to the other members of the nest long formed a subject of great difficulty to naturalists; but they appear to be males and females, which are ready to assume sexual relations, and to become the progenitors or kings and queens of new communities. The neuters are, accordingly, quite distinct from the sexual forms, and do not pass through any similar developmental phases, but differ from the others, even in the egg, as has been already mentioned. Occasionally a new termitarium may be found, in which a king and queen are absent, and which contains workers only. These, however, gradually prepare the nest for full completion, by bringing eggs into the cells from a neighbouring termitarium, from which the due population of the colony will be in time produced.

Fig. 6.—White Ant (Termes bellicosus). Gravid female.

The exodus or swarming of the Termites appears to resemble more nearly that of the bees, although lake that of the true ants, it is more purely reproductive in its nature, and not so much connected with the departure of fully grown forms from a hive which has become inadequate to the comfortable accommodation of all its inmates. The lame, prior to the swarming, are fed and tended by the workers, the youngest larvae receiving the greatest share of attention. The workers apparently feed the larvae by injecting a fluid from their mouths into the larval cells; and in about a year after the deposition of the eggs the larvas become fully grown, and the period of the exodus arrives. The exodus generally takes place on damp evenings, or cloudy mornings, and many extend over several days, or until such time as all the males and females have emerged from the nest. Having reached the ground, the wings of each ant are shed by a natural effect a seam or place of separation existing at the roots of the wings and after