1902.] NATURAL SCIENCES OF PHILADELPHIA. 609 



ants are hatched from sequestered piipse, aud reared without associa- 

 tion with older ants, they always drag old ants of their own line- 

 age away from the inert young, and sometimes refuse for" many days 

 to tolerate them near the nursery. The workers, on the other 

 hand, never drag younger ants of their own maternal lineage away 

 from the nursery, nor do they retaliate when the callows attack 

 them. I have seen a very small pale callow tyrannize over a large 

 deeply-colored adult for consecutive weeks. 



A cause for the hostility of one colony to another of the same spe- 

 cies and variety is a difference of odor, coincident with difference of 

 age in the individuals composing the colony. 



A queen, after mating, may settle in new ground, deposit her 

 eggs, rear from them her progeny, and herself determine the in- 

 herent hereditary odor of the colony, which will be the sanie for all 

 ants of that queen's lineage hatched at about the same time. 

 Such progeny may be separated aud kept segregated in sections for 

 long periods, and the individuals of any section will at once affili- 

 ate with those of any other section on reunion. The pupse may 

 be segregated, and the subsequent affiliation of the ants produced 

 therefrom will be equally complete, whether a queen be included 

 in each division or not. The progeny of sister queens of the same 

 age will instantly affiliate with each other or \nih. the aunt-queen, 

 provided that the segregation of each division has been perfectly 

 maintained, and that there is little difference in the age of the 

 ants. 



Attacks made upon ants of the same lineage, when such are intro- 

 duced into a segregated group, are more or less violent in proportion 

 to difference of age between the residents and the introduced mem- 

 bers. 



A group may rear successive broods, in successive seasons, from 

 the eggs of the same queen, and these broods Avill from their 

 earliest days to their latest recognize the odor of all the kindred 

 with which they were associated during the first few days of active 

 existence. Their standard of compatibility is then formed, and 

 they will defend nest and young against the approach of all ants 

 whose odor disagrees with that standard. It follows that ants in a 

 nest containing queens and workers many years old would have a 

 ■different standard from that of any more lately established nest, 

 even though all were of the same lineage. This explains the fact 



