242 A. M. FIELDE. 



Nest -Bj. - - On April 5, 1904, over six months after the segre- 

 gation of the Cremastogasters, there were about fifty workers in 

 their nest, 63. I then introduced two Lasius, with whom they 

 had lived in amity some forty days, and from whom they had been 

 separated over six months. The residents attacked the visitors 

 from nest B2, and would have slain them had I not rescued 

 them. There was no room for doubt concerning the absence of 

 recognition among the Cremastogasters of the present odor of the 

 Lasius, ants presenting an odor so strong that a single one of 

 them is very impressive to human nostrils. I was unable at that 

 time to introduce to these Cremastogasters any Lasius latipes 

 younger than were those with whom they had formerly associated. 

 But on August 12, 1904, when I introduced a newly-hatched 

 Lasius latipes of the X colony, they immediately killed it. On 

 August 20, 1904, I introduced a young Lasius from the wild 

 nest of the F colony, a sister of the one put on the 1 8th into nest 

 Bi. This ant was amiably received. The Cremastogasters rec- 

 ognized an odor from which they liad been eleven months sep- 

 arated. On the same day, August 20, 1904, I also introduced 

 an adult Lasins, of unknown age, but also of the F colony, one 

 of the nurses of the newly-hatched ant already accepted. This 

 adult Lasins was killed during the ensuing night. 



On April 8, 1904, I introduced to these Cremastogasters, in nest 

 63, two of the Stenammas with whom they had pleasantly lived 

 for forty days, in the preceeding autumn, and from whom they 

 had been separated more than six months. One of the visitors 

 behaved as if in an alien nest, showing fear and attempting to 

 escape. The other fought with a resident. Absence of recogni- 

 tion on either side indicted such change of odor during the period 

 of separation as to render these ants unacquainted with one an- 

 other. 



Early in July, 1904, I was able to introduce to this nest 

 several newly-hatched Stenammas from the wild nest of the C 

 colony, kindred of the ants in nest Bi. There were many queens 

 in that wild nest. That the callows might not bear the odor of 

 older ants, I segregated some pup?e, and offered the callows 

 newly hatched therefrom to the ants in nest 63, but these cal- 

 lows were all killed and dismembered within a few days after 



