1902.] NATURAL SCIENCES OP PHILADELPHIA. 611 



cell as equivalent to the casting out of that ant from the nest. I 

 sometimes lifted the cover and allowed the resident ant to carry an 

 intruder outside it. The Petri cells permitted more close and con- 

 stant observation of the ants concerned than would have been pos- 

 sible in any other residence. 



Experiment m. — On August 25, into a cell containing forty 

 workers, hatched between July 4 and July 16 from pupse previ- 

 ously segregated, 1 put one by one three workers, each twenty days 

 old, also hatched from sequestered pupse, and also segregated to 

 the time of the experiment. The introduced ants were all accepted 

 without examination or attention. 



I then put in a queen, captured June 7, and since dealated. 

 She undertook at once to sort the resident workers, and to carry 

 some of them out of the cell. She was attacked by a resident and 

 I removed her. 



I then put in an ant over one year old. She was seized and 

 dragged across the cell, and this was repeated three times on her 

 approach to the young, after whicli I removed her. 



I then put in another ant over a year old. Five residents 

 attacked her at once and so violently that I rescued and removed 

 her. 



I then put in a queen one year old. She was seized and dragged 

 across the cell and I removed her. 



I then put in another queen of the same age and she was treated 

 likewise. 



Experiment n. — On August 25, into a cell containing fourteen 

 workers, all hatched on August 5 from segregated pupae, I put a 

 marked ant less than thirty days older than the residents. She 

 was accepted without examination. I then put in a queen hatched 

 on the same day as were these residents, and since mated and 

 dealated. She was instantly accepted into the ant-group. 



I removed her, and put in a queen one year old. She was three 

 times dragged by two residents away from the young and across the 

 cell, and I took her out. This queen had mated with a king of 

 an alien colony, and had since reared progeny. 



I then put in another queen, a year old, who had mated with a 

 king of her own colony, and had since reared progeny. She was 

 likewise attacked and dragged. 



I put in adults of various ages, all more than a month older 



