No. 529] ORGANIC RESPONSE 19 



been tested. Using similar excitation Morgan induced 

 the appearance of white eyes and of short wings in a pedi- 

 gree culture of the fly, Drosophila ampelophila. Both 

 qualities were sex-limited and mendelized when paired 

 with the red eyes and long wings of the original type. 

 Both however seem to he fully transmissible. 13 



A related phase of the subject is that of the interposi- 

 tion of environic factors in mutations and hybridizations. 

 DeVries has repeatedly called attention to the fact that 

 the composition of hybrid progenies of mutants with 

 each other and with the parental form might be altered 

 by nutritive conditions, and the author has cited the fact 

 that mutations were made by Oenothera Lamarckiana 

 in the climate of New York which had never been seen 

 in Amsterdam. Furthermore, in discussing the diver- 

 gent results of DeV ries and myself, obtained by crossing 

 the same forms in Amsterdam and New York, the sug- 

 gestion was made that "the manner in which the var- 

 ious qualities in the two parents are grouped in the prog- 

 eny might be capable of a wide range of variation. 

 Many indications lead to the suggestion that the domi- 

 nancy and prevalency, latency and recessivity of any 

 character may be more or less influenced by the condi- 

 tions attendant upon the hybridization; the operative 

 factors might include individual qualities as well as ex- 

 ternal conditions." 14 



Using abnormal temperatures for excitation, Kammerer 

 induced color changes in Lacerta constituting female di- 

 morphism in one species, and male dimorphism in another, 

 and the newly induced characters, like the original ones, 

 behave in a mendelian manner in crosses, although the 

 heredity has not been carried through enough generations 

 to test their permanence. 1 5 



"MacDougal, Vail, Shull and Small. "Mutants and Hybrids of the 

 (Enotheras," Pub. No. 24, p. 57, Carnegie Inst, of Washington, 1905. 



"Vererbung erzwungener Farbenaenderungen. Arch-, f. Entwickl., Vol. 

 39, Hefte 3 and 4, p. 456, 1910. 



