182 Inheritance of Acquired Characters 
Similarly, how can one escape attributing the colors 
of butterflies’ scales to functional adaptaticn when one 
sees the golden red butterfly Polyommatus phlaeas change 
its color and take on a black tint merely from transporting 
it to warmer climates? 
Further, indubitable instances are known in which 
the color of the environment stimulates the outer surface 
of the animal directly or indirectly to take on the same 
color. Thus some arctic animals and birds become per- 
fectly white in winter, putting themselves thus in con- 
formity with the general color of the environment. 
Certain butterflies present phenomena of protective poly- 
chromatism in the sense that they always take on the 
color of their environment, and this should not appear 
strange for there is nothing inadmissible in the sup- 
position that a very sensitive skin can suffer much greater 
discomfort when the light rays which strike it are of a 
color different from its own than when they are of a 
like color with it. This discomfort would correspond 
to the disagreeable sense of heat or cold which makes 
itself felt over the surface of the body when its tem- 
perature difters from that of its environment. 
Consequently if every functional adaptation of the 
living substance to external agents consists in such a 
modification of its own vital processes that these find in 
the external agents no longer obstacles but rather co- 
operative stimuli, one can understand the tendency of 
every especially sensitive organ to make the color of 
its surface conform with that of its environment. This 
would not prevent the identity of colors from being of 
and Cesare Lombroso: Ancora dei caratteri acquisiti; Paguri, Cam- 
melli e Zebu. Rivista di Scienze Biologiche, Vol. II, No. 3. 1900. 
P, 2—3. 
