504 THE POPULAR SCIENCE MONTHLY. 



edge respecting the habit in question, as practiced by a certain species 

 of ant [Lasiusjfavus), which departs in a somewhat remarkable man- 

 ner from the habit as practiced by other species. lie says : " When 

 my eggs hatched I naturally thought that the aphides belonged to one 

 of the species usually found on the roots of plants in the nests of 

 Lasius Jiaviis. To my surprise, however, the young creatures made 

 the best of their way out of the nest, and, indeed, were sometimes 

 brought out of the nest by the ants themselves." Subsequent obser- 

 vation showed that these aphides, born from eggs hatched in the ants' 

 nest, left the nest, or were taken from it, as soon as they were hatched, 

 in order to live upon a kind of daisy which grew around the nest. 

 Sir John then made out the whole case to be as follows : 



Here are aphides, not living in the ants' nests, but outside, on the leaf -stalks 

 of plants. The eggs are laid early in October on the food-plant of the insect. 

 They are of no direct use to the ants, yet they are not left where they are laid, 

 where they would be exposed to the severity of the weather, and to innumerable 

 dangers, but are brought into their nests by the ants, and tended by them with 

 the utmost care through the long winter months until the following March, when 

 the young ones are brought out and again placed on the young shoots of the 

 daisy. This seems to me a most remarkable case of prudence. Our ants may 

 not perhaps lay up food for the winter, but they do more, for they keep during 

 six months the eggs which will enable them to procure food during the following 

 winter. 



As a supplement to this interesting observation, I may bere append 

 the following, wbicb is due to Herr Nottebohm, w^ho communicated it 

 to Professor Biichner : This gentleman had a w^eeping-asb which was 

 covered by millions of aphides. To save the tree, he one day in Marcb 

 cleaned and washed every branch and spray before the buds had burst, 

 so removing all the aphides. There was no sign of the latter till the 

 beginning of June, when he was surprised one fine sunny morning to 

 see a number of ants running quickly up and down the trunk of the 

 tree, each carrying up a single aphis to deposit it on the leaves, when 

 it hurried back to fetch another. " After some weeks the evil was as 

 great as ever. ... I had destroyed one colony, but the ants replanted 

 it by bringing new colonists from distant trees and setting them on 

 the young leaves." 



Aphides are not the only insects which are utilized by ants as cows. 

 Gall-insects and cocci are kept in just the same way ; but McCook ob- 

 served that, where aphides and cocci are kept by the same ants, they 

 are kept in separate chambers, or stalls. Caterpillars of the genus 

 Lyccena have also been observed to be kept by ants for the sake of a 

 sweet secretion which they supply. 



Slavery. The habit or instinct of keeping slaves obtains at least 

 among three species of ant. It was first observed by P. Huber in 

 Formica rufesceiis, which enslaves the species F.fiisca, the members 

 of which are appropriately colored black. The slave-making ants 



