1901.] NATURAL SCIENCES OF PHILADELPHIA. 533 



any other one of these queens, and all of the young ants would 

 congregate around any one of the sister-queens. 



Queens of the same colony have the same odor. Two queens, 

 each having a similar mixed family made up of her own and a 

 different stock, were interchanged with no disturbance of the 

 domestic life in either nest. 



Isolated queens of colony D reared each a few workers from 

 pupa3 of the C colony. The workers so reared w'ould live amica- 

 bly with any sister of the queen that reared them and also with 

 one another, 



A colony C queen and her issue reared two ants from pupje of 

 the E colony. When the two ants were a month old they were 

 removed from the fostering family and were introduced into a cell 

 containing a queen and adult workers of the C colony all deprived 

 of the smell-sense. The young ants at once snuggled the queen 

 and affiliated with the adults. They manifestly found in this 

 sister-queen and her workers the exact odor to which they were 

 accustomed. 



I took two queens of the C colony and segregated each with 

 pupie of the E colony. After the pupte had become ants fifteen 

 days old, an exchange of queens caused no demonstration of sur- 

 prise or of hostility. 



The inherent odor of the queens and that of the ivorkers in the 

 same colony is of like quality, though the odor of a queen is prob- 

 ably stronger than that of a worker. 



The behavior of kings in the nests proves them to be unable to 

 distinguish between queens and large workers. 



Workers removed from the C colony and segregated when eight 

 days old received amicably, after nine months of separation, the 

 two sister-queens in whose nests they had spent the first few days 

 of active life. Unless their own odor was similar to that of these 

 queens they must have had a personal memory of them. These 

 workers rejected queens of another colony. 



I isolated queens of the C colony and caused each to rear four 

 callows from pupre of the E colony. When the callows were six- 

 teen days old I introduced into every queen's cell two colony C 

 adults deprived of smell-sense. These adults were all received 

 amiably by the callows, indicating that they had the same sort of 

 odor as had the queen . 



