3 2 ° 



Thayer on Protective Coloration. 



TAuk 

 LOct. 



bathed in a yellow reflection from the earth, has the exact color, 

 as well as degree of darkness of his fop. Since, obviously, earth- 

 brown bathed in sky light, equals sky light (color of the animal's 

 belly) bathed in earth-yellow and shadow, i. e. brown. 



This grading to white under-surfaces is precisely what would 

 result if daylight tended to brown animals' coats, and its lack to 

 bleach them. And, from this, one might fancy the whole phenom- 

 enon to be the result of such browning and bleaching. But to 

 those who believe in Natural Selection it must be obvious that the 

 gradation's protecting-power proves it a result of such selection. 

 As to a bleaching and browning theory ; many facts suggest that 

 light does not tend to darken the coats of animals : Notice for 

 instance the pale inhabitants of treeless regions, such as sandy 

 beaches, etc., compared with wood-dwellers. But this discussion 

 is outside my present purpose. 



As an epigrammatic lash to my entire thesis on Protective 

 Coloration, it is important to say that no other conceivable 

 arrangement of light and dark colors could effect the intrinsic 

 unsubstantiality of appearance guaranteed by the gradation 

 therein set forth. 



