grounds on which they are resting. The well known 

 Chameleon, sold at County Fairs, possesses this faculty. 



Colors have ordinarily been placed into two cate- 

 gories: (1) Concealing colors and (2) Warning colors. 

 The purpose of the first is to render the animal invisible 

 or inconspicuous, while the second is supposed to be a 

 sign of ferociousness or formidability, by w^hich other 

 animals are warned to keep away. It is, in other words, 

 a danger sign. Certainly w^e can not place too much 

 confidence in the old idea of protective coloration, nor 

 can we concede to the claims of certain Physiologists 

 that such a thing does not exist. Modern knowledge 

 of colors shows that they, and the hair itself, are by- 

 products of animal metabolism. Thus the colors of 

 Mammals are definitely dependent upon a number of 

 factors, Physical, Chemical and Physiological. Tem- 

 perature, food, moisture and especially light, have 

 played their part in color production. While all of 

 these factors show^ more or less immediate efifects, it 

 must be remembered that definite color pattern did not 

 originate in a short time, but that its formation is the 

 result of many generations of gradual physiological 

 adaptations. There is thus a phylogenetic or racial 

 factor involved. 



Granting that color formation and deposition into 

 a definite pattern is chiefly physiological, insofar as its 

 immediate distribution is concerned, it is significant 

 that the colors of many forms are adaptive. Arctic 

 birds and mammals in their winter dress are white; 

 those of desert regions are usually a dull brownish 

 gray; forest animals are frequently striped; and those 

 of the open plains are nearly uniform in color. Cer- 

 tainly, the snow-w^hite coats of the Varying Hare and 



--HE 27 ><^- 



