BUCKINGELAM. — DIVISION OF LABOR AMONG ANTS. 4S9 



young, even in the out-door colonies when excited, but the minors 

 were fairly active. 



13. The greater activity in building was decidedly on the part of 

 the minors, though both classes carried earth and both dug. Prob- 

 ably the soldiers, with their large jaws, are better fitted to do this work 

 than they are to share in some other functions, such as tending the 

 young, for example, and hence their relatively increased activity in 

 this duty. 



14. There was no guarding of the kind observed in Colobopsis by 

 Wheeler and by Forel. However, when the entrances of the nests 

 were disturbed, both classes were inclined to rush out, though the 

 minors were somewhat the more active. 



15. When confined in Stender dishes it was found : First, that the 

 proportion of ants engaged in fighting is unusually large for both sol- 

 diers and minors. This is probably due in part to the difference of 

 methods from those employed for the other activities, the ants being 

 here confined in so small a space as to have a very large chance of 

 stimulation ; and in part to the nature of the activity, which is of 

 such a character that we should expect a large proportion of individ- 

 uals to share in it. Secondly, the soldiers were much more active in 

 fighting than were the minors, and they were more successful in grasping 

 the legs and antennae of Camponotus, while the minors seized the body 

 hairs of their enemies. On the other hand, in the field, the minors 

 seemed more successful in fighting with Lasius. The soldiers were 

 much more active in responding to disturbances caused by knocking 

 on the nest. 



16. In aluminum nests no soldiers were active in carrying or being 

 carried. In Barth nests, soldiers were dragged more commonly than 

 minors, but did not drag or carry other ants. 



17. The minors show greater activity in foraging and in all "house- 

 hold duties." 



18. The minors are much more lively in those activities in which 

 they share than are the soldiers. 



19. There is no hard and fast line between the duties undertaken 

 by separate classes, and in most duties all individuals are capable of 

 sharing. There is, nevertheless, in each activity a preponderance of 

 ants of a certain class taking part. 



B. Studies on Other Species of Pheidole. 



1. Methods. — Three colonies of Pheidole dentata, from Austin, 

 Texas, and one of Pheidole vinelandica, from Highlands, New Jersey, 

 were studied in exactly the same way as Pheidole pilifera in aluminum 



