ANTS AND ANT LIFE. 119 



receive just the same attention from ants ; and they, with 

 the other plant lice, yield the ants, in our countries, the 

 largest part of their food, although there is herein the 

 greatest diversity between the different species, and although, 

 as has been already said, the harvesting ants quite scorn the 

 Aphides. Some species (Ltptothorax, ColobopsisJ feed directly 

 on the juices of trees and plants ; some are carnivorous, as 

 Pheidole, Tapinoma, Tetramoriwn, and others, and prefer 

 putrefying bodies, dead insects, and similar comestibles to 

 sweet things. The gall insects are also kept by ants as 

 milch cows within their nests, and Me Cook found Cocci 

 as well as Aphides in the nests he examined ; they were, 

 however, kept in special, or separate rooms. The same 

 observer saw the caterpillars of butterflies belonging to the 

 genus Lycoena used as milch cows by a species of black ant 

 (.F. subsericeci), since these caterpillars yield a kind of sweet 

 liquid from minute glands in the abdomen. 



If ants are seen running up and down the branches of a 

 tree in great numbers, it is almost always only because 

 Aphides are to be found on the tree. They visit fruit trees, 

 for instance, only for the sake of the Aphides and gall- 

 insects, and do not touch uninjured fruit. Many attempts 

 have been made to destroy or hinder the clever little 

 creatures in this proceeding, partly to test their intelligence, 

 and partly to protect the trees from the injury inflicted on 

 them. How difficult it is to do this will be seen immediately. 

 They are indeed very easily frightened or startled away by 

 anything strange and unaccustomed, but this only lasts 

 until they have either recognised its harmlessness or learnt 

 how to overcome the obstacle. For instance, if a ring of 

 chalk be made round the trunk of a tree visited by ants, 

 those which first come to it are startled and do not venture 

 to cross the ring. But after a few of the braver have 

 looked carefully into the matter, and have found that there 

 is nothing to harm them, the rest follow them over the line. 

 Professor Leuckart put a more difficult, and apparently an 

 insuperable, obstacle in their way by spreading round the 

 tree-trunk a broad band soaked in tobacco-water. When 

 the ants coming from above arrived at the spot whereat this 

 obstacle awaited them, they turned back and let themselves 

 drop from the twigs of the tree and so arrived on the ground. 

 But it was not to be so easily managed by the ants coming 



i 2 



