1902.] NATURAL SCIENCES OF PHILADELPHIA. 607 



taken from the ancestral nest in the preceding August. Each of 

 the two residents instantly attacked an introduced adult, and used 

 their stings with such violence that 1, removed the adults through 

 fear of endangering the lives of the junior ants. I then introduced 

 two other workers, also of the C colony, but less deeply colored 

 than those I had removed. The two parties avoided each other, 

 always associating by twos during several hours ; but within a day 

 they were huddled in one group. Three days later I put the four 

 into a C colony nest, and they were all amicably received there. 

 There was difference of odor, perceived at the first meeting, 

 although all the ants were of the same colony. 



Experiment h. — May 9. Into a clean Petri cell I put five workers, 

 from twelve to fourteen days old, the progeny of a C colony queen 

 and an E colony king. With them I put five workers, four of 

 them from twelve to twenty-five days old, one of them sixty-five 

 days old, the progeny of a C colony queen and a C colony king. 

 The two groups had each been segregated from the pupa stage of 

 existence. All the nine ants that were less than twenty-six days 

 old afliliated quickly. The oldest ant Avas repeatedly attacked by 

 the ants that had not previously been associated with her, and was 

 dragged unresisting from the group and cast down on the opposite side 

 of the cell. After being thus ostracized for about three days she was 

 received into full fellowship. As this ant had the same parentage 

 and had spent all her life in segregation with the four younger ants 

 that were at once accepted into full fellowship, her age appears to 

 be the sole cause of her having been differently treated, and indi- 

 cates a different odor due solely thereto. 



Experiment i. — June 14. Into a Petri cell occupied by three 

 workers, ten days old, the progeny of a C colony queen and an 

 E colony king, and engaged in the care of introduced larv?e, 

 I put a worker, also ten days old, the offspring of a C col- 

 ony queen and a C colony king. There was instant affiliation. 

 I then introduced one by one ants of about the same age, but of 

 diverse paternity, the mothers all being of the C colony, and all 

 were amicably received, and were permitted to at once join in the 

 care of the larvse. When the group numbered ten, I added from 

 a nest of the C colony a queen and an adult worker. Both were 

 at once attacked and dragged away to the side of the cell opposite 

 the larvse. The queen was soonest tolerated, and within a day or 



