1906.] Wheeler, Founding of Colonies by Queen Ants. 95 



odor). She assumes on the part of the ants not only a highly devel- 

 oped associative memory for these various odors, but also a trans- 

 mission of odors by heredity. In other words, we must suppose 

 that every worker has an individual odor, which is continually 

 changing with age, and identical only with the odor of the other 

 workers of the same age and lineage in the same colony. I am 

 not prepared to deny the existence of all these odors, although I find 

 it difficult to understand how animals even as highly endowed as ants 

 can behave with anything approaching diagrammatic accuracy in the 

 presence of such a bewildering multiplicity of stimuli. The facts 

 certainly appear to be much simpler than the hypothesis which Miss 

 Fielde advances for their explanation. It would seem that the specific 

 and nest odors and the reactions which they call forth would be amply 

 sufficient to prevent two or more colonies of the same or different 

 species from fusing to form a single colony. This interpretation, 

 which is really the basis of Miss Fielde's elaborate schema, has long been 

 accepted by myrmecologists and repeatedly applied to particular cases. 



Second, while so much of Miss Fielde's contention may be granted, 

 there can be no question that she has failed to account for the numerous 

 exceptions which Forel, Wasmann and myself have been endeavoring 

 to elucidate. These she practically ignores. The species used in her 

 experiments, at least so far as they are mentioned in her paper, are 

 well known nonsymbiotic species. Nor does she refer to any of the 

 recorded cases in which female ants have been shown to be readily 

 adopted by adult workers of the same species from very different 

 colonies. In some of our species such adoptions may be immediate 

 and complete, for example in Stigmatomma pallipes, Pogonomyrmex 

 molefaciens, Eciton schmiiti, Leptothorax enter soni and Myrmica brev- 

 inodis, according to my own observations, and in Atta sexdens accord- 

 ing to Huber (vide supra, p. 46). 



Third, the cases just cited, together with the adoption of queens 

 by adult workers of alien species, of which several examples are 

 recorded in this paper, are facts, and can only be explained by as- 

 suming on the part of the adult ants a very considerable amount 

 of plasticity and adaptability to unfamiliar odors. It seems to me 

 that Miss Fielde fails to make due allowance for this factor in her in- 

 terpretation. This plasticity is conspicuously attested and exploited 

 by the hundreds of myrmecophilous insects known to science. The 

 toleration and adoption of the females of ants like Aner gates atratulus 

 and other workerless species, which are not only obligatory but per- 

 manent inquilines, Leptothorax emersoni and Formica consocians, 



