96 The Animal Mind 



mothers and have the differentiated worker odor. A young 

 ant isolated from the pupa stage until many days old will 

 single out its queen mother from queens of other species, 

 but will show decided suspicion of older sister worker ants. 

 A mixed nest formed of newly hatched ants of different 

 species was separated for seven months. On rejoining each 

 other, the ants showed hostility ; their odor, Fielde argues, 

 had changed. But young ants of one species were received 

 by those of the other species. Fielde does not hesitate to 

 introduce the psychic factor and say that the latter remem- 

 bered the odor of the young ones, having been associated with 

 it in their own youth. The suggestion might be made that 

 the young ants had not as yet developed any specific odor, 

 but this is opposed by the observation that newly hatched 

 Lasius ants from a strange colony were not received by a nest 

 of Stenammas, while young Lasius ants from a colony with 

 which the Stenammas had been acquainted in youth were 

 accepted eleven months after the latter had been segregated. 

 It is an affair of the memory, Fielde is assured ; and she says, 

 "If an ant's experience be narrow, it will quarrel with many, 

 while acquaintance with a great number of ant odors will 

 cause it to live peaceably with ants of diverse lineage, pro- 

 vided the odors characterizing such lineage and age environ 

 it at its hatching" (123). Bethe held that an ant's own nest 

 odor offered no stimulus to it at all, but that fighting reflexes 

 were occasioned by any foreign nest odor (30). Many facts, 

 however, seem to tell against this view; among others, the 

 early observation of Forel that a Myrmica ant deprived of 

 its antennae attacks everything in sight (130). It should, 

 according to Bethe's theory, live peaceably with all. 



Thus we see that in spite of some divergence of testimony, 

 there is evidence that ants have a variety of qualitatively 

 different smell experiences : the smell of food and of larvae, 



