1 66 HYMENOPTERA 



CHAP. 



given accounts -of some points in the economy of these ants. 

 They are amongst the largest of the Formicidae, the females in 

 some cases measuring about two and a half inches across their 

 expanded wings ; the males are much smaller, but are less dis- 

 similar to their partners than is usual among ants. The workers, 

 on the other hand, are so extremely different, that no one would 

 suppose them to be at all related to the males and females (see 

 vol. v. Fig. 339). 



The mode of operation of these ants is to form paths from 

 their formicary extending for a considerable distance in various 

 directions, so that they have a ready access to any spot in a 

 district of considerable extent ; when a tree or bush is found 

 bearing leaves suitable for their purposes, the worker ants ascend 

 it in large numbers and cut up the leaves by biting out of them 

 pieces similar in size and shape to a small coin ; these pieces are 

 then carried back in the jaws of the ants to their nests ; the ant- 

 paths are therefore constantly traversed by bands of little creatures 

 carrying burdens homewards, or hurrying outwards in search of 

 suitable trees. 



The formicaries are of considerable size, and are described 

 as consisting of low mounds of bare earth of considerable extent. 

 Bates speaks of as great a circumference as forty yards ; these 

 accumulations of earth have frequently an appearance different 

 from the adjoining soil, owing to their being formed of subsoil 

 brought up from below ; they are kept bare by the ants con- 

 stantly bringing to and depositing on the surface fresh material 

 resulting from their subterranean excavations. The true abodes, 

 beneath the earth, are of greater extent than the mounds them- 

 selves, and extend to a considerable depth ; they consist of 

 chambers connected by galleries. 



The leaf -cutting ants extend their range to Xorth 

 America, and M'Cook has recently called attention to a case 

 there in which A. ferrens made an underground route at an 

 average depth of 18 inches, and at an occasional depth of 

 feet, extending 448 feet entirely beneath the earth, after which 

 it was continued for 185 feet to reach a tree which the ants were 

 engaged in defoliating. This route, extending altogether to a length 

 of more than 600 feet, presented only a very slight deviation 

 from a straight line drawn between the point of departure and 

 the object to be attained. By what sense this ant was enabled 



