I 1 6 ORGANIC E VOL UTION 



found among the fossils of the northern hemisphere. It 

 would at first thought seem preposterous to postulate the 

 former presence of such a connecting continent with no more 

 evidence in its favor than the resemblance between these 

 fossil faunas. Yet this line of evidence has proven so trust- 

 worthy in other instances that some of our most conservative 

 paleontologists are inclined to accept the evidence in this 

 case and to believe that such a continent once existed. 



Color in animals. 



The phenomena of color in both animals and plants are 

 among the most remarkable and interesting in the whole 

 realm of nature. It is not so much the way in which the 

 color is produced, whether by pigments or by refraction, that 

 interests us in this connection, as it is the uses to which the 

 colors are put. Let us first refer to the colors of animals. 



According to the uses to which colors of animals are 

 put, we may classify them, for purposes of description, as 

 follows : 1 



Indifferent colors, not useful, so far as we can judge; 



Colors of direct physiological value ; 



Protective colors and resemblances ; 



Aggressive colors and resemblances ; 



Alluring colors and resemblances ; 



Warning colors ; 



Mimetic colors and resemblances ; 



A, Protective, 



B, Aggressive ; 



1 In the main I have followed the classification used in Poulton's delightful book 

 The Colors of Animals. 



