34° Adaptation to Environment 



Megusar 1 has repeated Kammerer's experiments on 

 salamanders but contradicts him by stating that the 

 colour of the soil has no influence on the colouration 

 of salamanders. Of course, we know the phenomenon 

 of colour adaptation in which the animal changes its 

 colour pattern according to the environment. This 

 is an effect of the retina image on the skin and has been 

 interpreted by the writer as a case of colour tele- 

 photography, for which no physical explanation has 

 yet been found. 2 This phenomenon, however, does not 

 lead to any hereditary change of colour. 



Kammerer makes many statements on the heredity 

 of acquired modifications of instinct; indeed he claims 

 that an interest in music on the part of parents pro- 

 duces offspring with musical talent. In such claims 

 much depends upon the subjective interpretation of 

 the observer. 



The writer is not aware that there is at present on 

 record a single adequate proof of the heredity of an 

 acquired character. We have records of changes in 

 the offspring by poisoning the germ plasm by alcohol 

 given to parents — as in Stockard's well-known experi- 

 ments — or by exposing butterflies to extreme tempera- 

 tures, but in these cases the germ cells were poisoned 

 or altered by the alcohol or by chemical compounds 

 produced at very low or very high temperatures. This 



1 Werner, F., Biol. Centralbl., 1915, xxxv., 176. 



2 Loeb, J., The Mechanistic Conception of Life. Chicago, 1912. 



