4 ADELE M. FIELDE. 



longed effort on the part of the workers to placate the queen- 

 mother. They surrounded her at all times, offering her regurgi- 

 tated food. Whichever way she turned, there stood a humble 

 servant with a proffered mouthful of pabulum. As many as 

 seven workers simultaneously offered nourishment to her. Every 

 worker of the eleven seemed bent upon wooing and winning her, 

 and she was not for a moment left without attention. These 

 efforts were unceasingly continued, and were meeting with a fair 

 degree of success, when I removed the queen on the following 



morning. 



This experiment showed that the workers all recognized the 

 odor of their queen after two years of separation from it, and that 

 the segregated workers had during the same interval acquired an 

 odor unfamiliar to the queen, who had meanwhile met none of 

 her daughters who were over fifteen months old. It also showed 

 that major workers, having in this species nearly the same form 

 and sometimes nearly the same bulk as has the queen, are like 

 minor workers in having a progressive odor. 



On August 7 I introduced into this Ni group a marked major 

 and a marked minor worker, daughters of the N queen, but 

 many months younger than any of the ants in this group. The 

 visitors were received with signs of curiosity, but with perfect 

 amiability, though no younger sisters had been encountered 

 within two years by these Ni ants. The odor of the younger 

 sisters was perfectly recognized by the eleven residents, and I 

 removed the former. 



I then introduced a young winged queen of the same species, 

 Camponotns pennsylvanicus, but of an alien colony. The resident 

 ants attacked her instantly and with exceeding virulence. In an 

 instant she lost an antenna, one worker was pulling out her 

 remaining antenna, and three others were dragging her by her 

 legs. The scrimmage was fierce, and before I removed the in- 

 truder four of the residents had received injuries that resulted 

 in their deaths. The residents had given to the alien queen 

 a reception strongly contrasted with that accorded to their own 

 queen-mother ; while the havoc wrought by the alien queen 

 indicated that, if unable to escape from the nest, she might have 

 destroyed all the workers and have remained a fostering mother 

 to their larvae. 



