BUCKINGHAM. — DIVISION OF LABOR AMONG ANTS. 485 



On only a few occasions did I see minors feeding themselves, and 

 soldiers never ; nor did I see the latter receive any regurgitated food. 



The small ants were much more likely to lick other ants than were 

 the soldiers, of which I saw only one engaged in this performance. The 

 minors were just as much inclined to lick one class as the other. 



Though I did not see many ants engaged in building, there was a 

 division of this kind of labor between the two classes. The carrying 

 of earth was all done by the minors, whereas all the digging observed 

 was the work of soldiers (four individuals, not all from the same 

 colony). The digging consisted of using the front feet, much as a dog 

 does in digging a hole in the ground, and also in breaking off pieces 

 of earth with the jaws. I have also seen soldiers, by squeezing their 

 way through narrow passages in the galleries, loosen earth, which the 

 minors then carried away. 



Only minors have been seen dragging other ants, and only soldiers 

 were being dragged. Had those which were being dragged been small 

 enough, they probably would have been carried, for this activity seems 

 to correspond to that which is properly called "carrying" in cases 

 where the ants being transported are small ; such, for example, as were 

 observed in this species, both in aluminum nests and in the field, and 

 likemse in Camponotus (p. 468). 



To sum up the facts concerning the relative participation of the two 

 classes in the various activities as far as observed in Barth nests, it 

 may be stated that all the digging was done by soldiers, and that they 

 were more excited in responding to disturbances of the nest, but that 

 in all other functions they were less active, not sharing at all in some 

 of them. There was no evidence of guarding. 



iii. Out-door Work on Pheidole pilifera. 



1. Methods. 



Essentially the same methods were used in studying Pheidole 

 pilifera as in that of Camponotus pictus, except that, owing to the 

 distinctness of classes, it was possible to make and record final obser- 

 vations as to class without the necessity of killing and preserving 

 for subsequent study so large a number of ants observed in the dif- 

 ferent activities. There are occasionally individuals intermediate 

 in form between the extreme classes, but they are so rare as to cause 

 no danger of confusion. I have had so little chance to observe them 

 that I am not prepared to say just what their functions are. Fre- 

 quently records were made of the number of ants of each class in a colony 

 seen engaged in a given occupation during a certain period, usually of 



