Adaptation to Environment 339 



to examine the evidence for the inheritance of acquired 

 characters more seriously. I wrote to Dr. Kammerer in 

 July, 1 910, asking him for the loan of such a specimen and 

 on visiting the Biologische Versuchsanstalt in September 

 of the same year I made the same request, but hitherto 

 none has been produced. In matters of this kind much 

 generally depends on interpretations made at the time of 

 observation; here, however, is an example which could 

 readily be attested by preserved material.^ 



More recently the same author has reported another 

 hereditary morphological change brought about by 

 outside conditions.^ A certain salamander {Salaman- 

 dra maculosa) has yellow spots on a generally dark 

 skin. Kammerer states that if such salamanders are 

 kept on a yellow ground they become more yellow, 

 not by an extension of the chromatophores (which would 

 not be surprising) but by actual multiplication and 

 growth of the yellow pigment cells; while the black 

 skin is inhibited in its growth. The reverse is true if 

 these salamanders are kept on black soil; in this case 

 according to Kammerer the growth of the yellow cells 

 of the skin is inhibited while the black part of the skin 

 grows. Curiously enough, according to him, these in- 

 duced changes are hereditary. Here again we are deal- 

 ing with the inheritance of an acquired morphological 

 character. 



^ Bateson, W., Problems of Genetics, pp. 201-202. Yale University 

 Press, 191 3. 



* Kammerer, P., Arch. f. Entwcklngsmech., 1913, xxxvi., 4. 



