I36 ADELE M. FIELDE. 



another, and the younger sisters were supposed by me to have 

 become reconciled to the progressive odor of their seniors. But 

 after being united in an apparently congenial family group, a 

 senior worker was occasionally killed by a junior, and successive 

 conflicts utterly destroyed the colony after several months. 



I have repeatedly observed the gradual dwindling and extinc- 

 tion of apparently healthy ant-groups in which the individuals 

 bore odors not wholly familiar to all the inhabitants. Into 

 an artificial nest of Camponotus herculaneus, in which the occu- 

 pants were all virgin workers, who had never before met a male 

 of their species, I introduced several males. The first impres- 

 sion of an inexperienced observer would probably have been that 

 the workers attacked the males with intent to tear them limb 

 from limb. F"or some hours the attacks were maintained ; but 

 the males remained unscathed and, without even a rent in their 

 delicate wings, continued for weeks in close companionship with 

 the workers. It was attraction, not antipathy, that dictated the 

 violent behavior of the workers. 



The presence of young ; the completeness of the establish- 

 ment of the nest-aura ; the domestic conditions in general ; the 

 familiarity of the ants with their immediate environment ; the in- 

 curred odor ; the inherited odor ; the progressive odor ; the spe- 

 cific odor ; the sensitivity of the ants to a preponderating odor 

 and their encouragement or discouragement therefrom ; the apt- 

 ness of ants to concentrate attention upon an immediate interest 

 and to become temporarily oblivious to other matters ; and the as- 

 sociative memory maintained by every ant concerning its previous 

 experiences, are all factors which need be weighed when deter- 

 mining the causes of the behavior of ants. 



E. When making inquiry of the ants concerning their sense 

 of hearing in the summer of 1903, I deprived the ants of por- 

 tions of their bodies and found that the excision of certain parts 

 uniformly affected the direction of the movement of the ants 

 when they were startled. 1 Normal queens (of Stenamma fulvurn) 

 moved either forward, backward or sidewise, while queens de- 



1<( The Reactions of Ants to Material Vibrations," by Adele M. Fielde and 

 George H. Parker, Proceedings of the Academy of Natural Sciences of Philadelphia, 

 November, 1904, p. 646. 



