270 MANUAL OF ZOOLOGY. 



which the males die. The females then lose their wings and 

 fall to the ground, when they become the queens of fresh 

 societies. In some Ants, as in the Termites, the neuters are 

 divided into two classes^the workers and the soldiers — of 

 which the former perform all the duties necessary for the pre- 

 servation of the society except defending the nest, this being 

 left to the soldiers. In other cases, as many as three distinct 

 orders or "castes" of neuters may be present in the same 

 nest. 



Amongst the more singular of the habits and instincts qf 

 Ants two maybe mentioned — the instinct of making slaves, 

 and that of milking, so to speak, the little Plant-lice (Aphides). 

 As regards the first of these, it is found that certain Ants pos- 

 sess the extraordinary instinct of capturing the pupae of other 

 species of Ants, and bringing them up as slaves. The rela- 

 tions between the master and the slaves vary a good deal in 

 different species. In the case oi Formica rufescens, for instance, 

 the masters are entirely dependent upon their slaves ; the 

 males and females do nothing except reproducing the species, 

 and the neuters perform no other labour except that of captur- 

 ing fresh slaves. The masters are in this case unable even \.o 

 feed themselves, and their existence is maintained entirely by 

 the devotion of -the slaves. In Formica sanguinea, on the 

 other hand, the number of^ slaves is much less, and both 

 masters and slaves occupy themselves in performing most of 

 the duties necessary for the community. The masters, how- 

 ever, go alone when on slave-making expeditions ; and in case 

 of a migration, the masters carry the slaves in their mouths. 



A second singular fact in the history of Ants is found in the 

 relations which subsist between them and the Aphides, or 

 Plant-lice. The Aphides secrete, or rather excrete, a peculiar 

 viscid and sweet liquid, by means of a gland which is situated 

 towards the extremity of the abdomen, and communicates with 

 the exterior by two tubular filaments. Ants are extremely fond 

 of this excretion, and it is a well-established fact that the 

 Aphides allow themselves to be milked, as it were, by the Ants. 

 For this purpose the Ant touches and caresses the abdomen 

 of the Aphis with its antennae, whereupon the latter voluntarily 

 exudes a drop of the coveted fluid. Ordinarily the Ants seek 

 the Aphides upon plants ; but it is asserted that in some cases 

 they keep Aphides, much in the same way as human beings 

 keep cows — though this is probably partly imaginary. 



Order XI. Strepsiptera. — Females without wings or feet, 

 parasitic. Males possessing the posterior pair of wings, which 

 are large, membranous, and folded longitudinally like a fan. 



