236 A. M. FIELDE. 



marked Ai, three large and vigorous workers, without young. 

 I then introduced two Stenammas that the Camponotus had 

 known in the previous September in the A nest. The Ste- 

 nammas manifested terror and the Camponotus made instant 

 and violent attack upon them, so that I intervened in the ensu- 

 ing battle, saved the lives of the Stenammas, and returned them 

 to their own nest. It was evident that during the six and a half 

 months of separation these ants had changed in odor, and that 

 the odor borne by them in April was unknown to the ants with 

 whom they had associated in the previous September. I was 

 unable to offer to this group Ai the companionship of young 

 Stanammas having the same odor as had their former associates 

 at the time of association, and young Stenammas taken at a later 

 date from the wild nest in the summer of 1904, were always 

 killed by them. The Formicas were likewise rejected. 



Nest A2. The Formicas that had lived, none less than 

 twenty and none more than forty-one days, in nest A, were dom- 

 iciled in nest A2. They had been separated from the Campono- 

 tus six and a half months, when on April 8, 1904, I introduced 

 into their nest, where there were twenty-six workers and no young, 

 a Camponotus from nest Ai, comrade of their earliest days. The 

 Formicas immediately attacked the Camponotus, and I removed 

 the latter to save her life. Six month's progress in odor forma- 

 tion had carried her outside the acquaintance of her former asso- 

 ciates. The same antagonism was manifested toward the other 

 two residents in nest A I . 



These Formicas continued to reside in their nest and had laid 

 a few eggs, which were under their c;ire when on April 25, 1904, 

 I introduced to their nest three Camponotus newly hatched from 

 eggs that were laid in August, 1903, by the queen-mother of the 

 Camponotus in nest Ai. These young Camponotus received 

 amiable welcome from the resident Formicas, and during the 

 next ensuing days, to May 10, I added several more callows. The 

 Formicas, now eight months old, continued to live amicably with 

 the young Camponotus, whose odor had been known to them in 

 their earliest days. They regurgitated food to the young ants, 

 permitted them to cany the egg-packet and care for the larvae, 

 and in all respects treated them as if of their own colony. There 



