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." 13 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 the 

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

 ment, but, according to Miss Ficlde, they can detect 'pro- 

 gressive odors' due to change of physiological condition 

 with the age of the individual." 12 



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 may In- 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." 14 



To Ernest Seton is due credit for the nearest approach 

 that has been made to a scientific application of this method 

 of discovering chemical differences between animals of the 

 vertebrate orders. The theory of what he calls scent- 

 language is founded on his studv of carnivorous animals 

 which limit by smell. 



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

 which individual animals of the same- group distinguish one 

 another, neglect the case of the human anima!. 



