406 THE DESCENT OF MAN. 



spotted with black; in the female these parts are pale gray- 

 ish green without spots."* We have seen that the males 

 alone of Sitana possess a throat-ponch; and this is splen- 

 didly tinted with blue, black and red. In the Proctotretus 

 tennis of Chili the male alone is marked with spots of blue, 

 green and coppery red. f In many cases the males retain 

 the same colors throughout the year, but in others they 

 become much brighter during the breeding-season; I may 

 give as an additional instance the Calotes maria, which at 

 this season has a bright red head, the rest of the body being 

 green. J 



Both sexes of many species are beautifully colored exactly 

 alike; and there is no reason to suppose that such colors are 

 protective. No doubt 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 frightened, 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 reptiles 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. 



*Bell, "History of British Reptiles," 2d edit., 1849, p. 40. 



fFor Proctotretus see "Zoology of tlie Voyage of the 'Beagle;' 

 Reptiles," by Mr. Bell, p. 8. For the lizards of S. Africa, see 

 " Zoology of S. Africa: Reptiles," by Sir Andrew Smith, pi. 25 and 

 39. For the Indian Calotes, see " Reptiles of British India," by Dr. 

 Giinther, p. 143. 



tGuntherin "Proc. Zoolog. Soc.," 1870, p. 778, with a colored 

 figure. 



