Sensory Discrimination : the Chemical Sense 95 



in water, and then in the juices obtained by crushing the 

 bodies of a number of ants of another species. He found 

 that an ant thus treated would be attacked and killed by 

 its own nest mates, but could be introduced, though not 

 so easily, into the nest whose odor it now presumably bore, 

 even though its appearance was quite different from that 

 of the ants therein (30). Wasmann repeated these experi- 

 ments with much less success than Bethe ; bathing Myrmica 

 ants with essence of Tetramorium ant did not preserve 

 them from final destruction at the jaws of the latter, 

 though it delayed their fate; nor did much bathing with 

 foreign nest odors induce their nest mates to attack ants 

 of the species Lomechusa strumosa, though they seemed 

 disturbed at first. Wasmann apparently thinks other fac- 

 tors besides smell, vision perhaps, enter into the recogni- 

 tion process (426). Bethe, in a later paper, suggests that 

 Wasmann's negative results may have been due to the fact 

 that the nest smell very quickly returns to the ants after 

 it has been removed ; he himself took account only of the 

 first reaction of other ants toward the one subjected to 

 treatment (31). 



Fielde, as the result of a study of the genus Stenamma, 

 concludes that each ant is the bearer of three distinct odors : 

 the individual odor, which enables her to follow her own 

 trail in a labyrinth, and the reception of which depends upon 

 the tenth segment of the antennae ; the race odor, depend- 

 ent on the eleventh segment; and the nest odor, depend- 

 ent on the twelfth (118). In a later article she concludes 

 that the nest odor of the worker ants is derived from their 

 queen mother; that the odor of the queen is unchanging, 

 and is imparted to her eggs. The worker, however, gradually 

 changes its odor. Queens of diverse odors may be produced 

 by the influence of males that are the offspring of worker 



