BUCKINGHAM. — DIVISION OF LABOR AMONG ANTS. 473 



were rather light-colored, and some gave evidence of being very young, 

 their color being in general pale, even in the legs. On the other hand, 

 those which were doing the carrying were almost universally dark, and 

 none of them were very bright. Those which were being carried were 

 probably more or less weak. 



6. When those which responded to disturbances of the nest were 

 examined, it was found that all had at least nearly reached the maxi- 

 mum depth of color, and most of them had quite reached that stage. 



Thus it may be seen that, as has been claimed for other species and 

 for ants in general, the young workers of this species sometimes build, 

 and sometimes are carried about ; but they are especially engaged in 

 tending the young (eggs, larvae, or pupae). Occasionally young indi- 

 viduals, though not the youngest, carry other ants, or are found in the 

 field, but only the fully colored ants share in defence. 



iv. Conclusions for Camponotus herculeanus pictus. 



To summarize the facts concerning Camponotus herculeanus pictus 

 when studied in Earth nests or by any of the methods used in the 

 field: 



1. No males were seen to share in the duties of workers. 



2. The very youngest ants take part especially in tending the eggs, 

 larvae, and pupae, and sometimes in building, and they are apt to be 

 carried by their companions, but they do not go into the field until 

 they are somewhat darker than the very young stages, though they 

 may do so while still retaining some brightness of color. The ants of 

 this species do not, however, enter into the defence of the nest until 

 they are dark. 



3. Only a small proportion of the whole number of ants in a colony 

 is engaged at one time in any activity. 



4. Though more ants in proportion to the size of tbe colony are 

 active in large colonies than in small ones, nevertheless this does not 

 seem to make a difference in the kind of individuals engaged in differ- 

 ent sorts of work, provided that the colony is of sufficient age to con- 

 tain ants of all sizes. It must be remembered, however, that in the small 

 colonies in artificial nests rather more large ants, in proportion to the 

 whole number participating, were engaged in the various activities 

 than was the case in out-door nests. 



5. All classes may take part in carrying food, but the intermediates 

 are the ones which do this most. Intermediates are also more likely 

 to be found in the field, apparently foraging. 



6. While individuals of all classes regurgitate food and receive re- 

 gurgitated food, it is probable that the two smaller classes, especially 



