354 THE DESCENT OP MAN. 



Both sexes of many species are lieautifully colored exactly alike; 

 and there is no reason to suppose that such colors are protective. 

 No douht with the bright green kinds which live in the midst of 

 vegetation, this color serves to conceal them, and in N. Patagonia 

 I saw a lizard (Proctotretus multimaculatus) which, when fright- 

 ened, flattened its body, closed its eyes, and then from its mottled 

 tints was hardly distinguishable from the surrounding sand. But 

 the bright colors with which so many lizards are ornamented, as 

 well as their various curious appendages, were probably acquired 

 by the males as an attraction, and then transmitted either to their 

 male offspring alone, or to both sexes. Sexual selection. Indeed, 

 seems to have played almost as important a part with rep- 

 tiles as with birds; and the less conspicuous colors of the females 

 In comparison with the males cannot be accounted for, as Mr. 

 Wallace believes to be the case with birds, by the greater exposure 

 of the females to danger during incubation. 



