POWER OF RECOGNITION AMONG ANTS. 237 



was no death in the nest for twenty days after the introduction of 

 the young Camponotus, but I removed them on June 25. The 

 Formicas recognized, after seven months of separation from it, an 

 ant-odor previously knozvn to them. 



I was unable to introduce to this nest any young Stenammas 

 that the Formicas would accept, as I could command none of 

 the same lineage and age as those known to them in the autumn 

 of 1903. The individual Stenammas in nest A3, with whom 

 they had formerly associated in the A nest, were now of another 

 odor, and the Formicas refused to affiliate with them. 



Nest Aj. - -The Stenammas in this nest had lived in nest A, 

 none less than twenty and none more than forty-one days, and 

 since September 24, 1903, they had met no ant other than those 

 in their own nest. On April 8, 1904, 1 introduced into their nest, 

 where, there were forty-one workers, a former comrade, a For- 

 mica from nest A2. She was fiercely attacked, and I removed 

 her. Other Formicas from the same nest were likewise attacked. 

 I then introduced Camponotus from nest Ai, and they were 

 received with like animosity. It was instantly made evident that 

 the resident Stenammas found in every visitor an unfamiliar odor. 

 I removed each visitor as soon as her status among these Sten- 

 ammas had been made plain, and the A3 nest remained quies- 

 cent until April 24, when I introduced a day-old Camponotus, 

 the issue of an egg laid the previous August by the mother of 

 the rejected individual in nest Ai. Within a few minutes after 

 its introduction, three of the Stenammas had licked the Campo- 

 notus, and all the Stenammas had viewed it with approval. It 

 was taken care of as tenderly as if it had been a Stenamma cal- 

 low. On the same day I added two newly hatched Camponotus 

 of the same lineage, and they were kindly entertained until April 

 27, when I removed them to another nest of Stenammas, the M 

 nest. These M Stenammas were of the same age and colony as 

 were the Stenammas in nest A3, differing from them only in 

 never having lived with Camponotus. There were also about 

 the same number of resident ants. As soon as I introduced the 

 Camponotus into the M nest, the Stenammas attacked them, 

 and although they were double the size of the residents, and of 

 tougher integument, the residents harried them to death. The 



