iv.] AGRICULTURE AMONG ANTS. 109 



The results may be tabulated as follows : 



Pupae brought up by friends Pupse brought up by strangers, 



and replaced in their own nest. Put in own nest. Put in strangers' nest. 



Attacked ... 7 1 15 



Received amicably 33 37 



I hope to make further experiments in this direction, 

 but the above results seem very interesting. They 

 appear to indicate that ants of the same nest do not 

 recognise one another by any password. On the other 

 hand, if ants are removed from a nest in the pupa state, 

 tended by strangers, and then restored, some at least of 

 their relatives are certainly puzzled, and, in many cases, 

 doubt their claim to consanguinity. Strangers, under 

 the same circumstances, would be immediately attacked ; 

 these ants, on the contrary, were in most cases some- 

 times, however, only after examination amicably re- 

 ceived by the majority of the colony, and it was often 

 several hours before they came across a single individual 

 who did not recognise them. 



Most of our European ants feed on honey, or on other 

 insects. Some few, however, store up grain. 



A Texan ant, Pogonomyrmex barbatus, is also a 

 harvesting species, storing up especially the grains of 

 Aristida oligantha, the so-called "ant rice/' and of a 

 grass, Buchlce dactyloides. These ants clear disks, ten 

 or twelve feet in diameter, round the entrance to their 

 nest, a work of no small labour in the rich soil, and 

 under the hot sun, of Texas. I say clear a disk, but 

 some, though not all, of these disks are occupied, 

 especially round the edge, by a growth of ant rice. 



1 About three of these I did not feel sure. 



