1915.] NATURAL SCIENCES OF PHILADELPHIA. 37 



the abode of her enemies until her life pays the penalty of her uncon- 

 scious temerity. This sub-nose appears to discern many odors, 

 diffused in the air. (See c, page 539.) 



(2) It is well known that ants of the same species abide in different 

 colonies or communities so hostile to one another that an encounter 

 between members of different colonies results in a battle, often 

 prolonged until one or the other is exterminated. The undeveloped 

 young of one colony are sometimes stolen and reared by the adults 

 of another colony of the same species, but the adults of different 

 colonies ordinarily maintain a mutual repugnance that is invincible, 

 no matter how long an artificially enforced companionship may 

 exist. The colony odor, depending on age, is discerned through 

 the penultimate segment of the antenna. When this segment is 

 elmiinated, ants of different colonies of the same species live and 

 work together in complete accord. They are then unaware of the 

 objectionable odor of their comrades, as they no longer perceive 

 what the normal ant discerns. The colony odor is discerned through 

 contact of the antenna with the body of the ant subject to examina- 

 tion. This eleventh segment is, or contains, an organ of chemical 

 sense which might be called olfactory or gustatory. (See b, page 

 449; c, page 531; d, page 609; t, page 1.) 



(3) When an ant goes out from her dwelling, she lays down from 

 her feet an odorous substance whereby she is guided on her return 

 journey. She discerns her own scent through the antepenultimate 

 segment of the antenna, and through the air. When this tenth 

 segment is eliminated she is no longer able to retrace her steps and 

 is completely bewildered. She is as incapable as is a dog in pursuit 

 of a master who has waded. (See c, page 522.) But in her case 

 the track remains, while power to pick up the scent has been de- 

 stroyed in the pursuer. 



(4) The next two segments of the funicle, the eighth and ninth 

 counted from the proximal end of the antenna of Stenamma fulvum 

 piceum, discern the odor of the queen and of the undeveloped young 

 ordinarily her progeny. When these segments are eliminated, the 

 worker ant, that in her normal condition evinced extreme devotion 

 to the welfare of the inactive young and to the queen-mother, becomes 

 wholly indifferent to all or any of those whom she has heretofore 

 served. There are indications that the inactive young, as well as 

 the queen, have a progressive odor, appreciable to the workers both 

 by contact and in the air, and that the odor is a distinctive one, 

 alluring to the workers. (See c, page 542; k, page 229.) 



