The Organism and its Chemistry 89 



have done for the ants, and von Buttel-Reepen for the bees, 

 that these animals in distinguishing their different nest- 

 mates and their enemies, betray nothing beyond the percep- 

 tion of extremely delicate and numerous gradations in the 

 qualities of odors." ^^ And continuing the statement quoted 

 from above relative to the odors of ants recognizable by 

 man, Wheeler says, "but these insects carry the discrimina- 

 tion much further. They not only differentiate the different 

 odors peculiar to species, sex, caste, and individual, and tlie 

 adventitious or 'incurred' odors of the nest and environ- 

 ment, but, according to Miss Fielde, tliey can detect 'pro- 

 gressive odors' due to change of physiological condition 

 with the age of the individual." ^^ 



Miss Fielde's formulation of her hypothesis referred to 

 by Wheeler is as follows: "1. The Specific Odor — The moth- 

 er-ant transmits to her offspring the distinctive odor which 

 is identical for ants of all ages and of both sexes within 

 the species. 2. Progressive Odor. — Female ants, including 

 queens and workers, have, beside their specific odor, an odor 

 which m^y be termed progressive. Queens of different lin- 

 eage have different progressive odors. In a queen this odor 

 is either unchanging or changes very slowly, and it is sim- 

 ilar to that of her newly hatched offspring. As worker- 

 ants advance in age their progressive odor intensifies or 

 changes to such a degree that they may be said to attain 

 a new odor every two or three months." ^'* 



To Ernest Seton is due credit for the nearest approach 

 tliat has been made to a scientific application of this metliod 

 of discovering chemical differences between animals of the 

 vertebrate orders. The theory of what he calls scent- 

 language is founded on his study of carnivorous animals 

 which hunt by smell. 



Nor can we, while on this subiect of odors as a means by 

 which individual animals of the same group distinguish one 

 another, neglect the case of the human animal. 



