402 THE DESCENT OF MAN. 



able to ascertain, is the general rule with lizards of all kinds. 

 The male alone of the Uyrtodactylus rulidus of the Anda- 

 man Islands possesses pre-anal pores; and these pores, judg- 

 ing from analogy, probably serve to emit an odor. * 



The sexes often differ greatly in various external charac- 

 ters. The male of the above-mentioned Anolis is furnished 

 with a crest which runs along the back and tail, and 

 can be erected at pleasure ; but of this crest the 

 female does not exhibit a trace. In the Indian 

 Cophotis ceylanica the female has a dorsal crest, though 

 much less developed than in the male; and so it is, as Dr. 



Giinther informs me, with the 

 females of many Iguanas, 

 Chameleons and other lizards. 

 In some species, however, 

 the crest is equally developed 

 in both sexes, as in the Iguana 

 tuberculata. In the genus 

 Sitana, the males alone are 

 furnished with a large throat- 

 pouch (fig. 33), which can be 

 folded up like a fan, and is 



33. sitana minor. Male with colored blue, black and red; 

 but these splendid colors are 

 exhibited only during the pair- 

 ing-season. The female does not possess even a rudi- 

 ment of this appendage. In the Anolis cristatellus accord- 

 ing to Mr. Austen, the throat pouch, which is bright red 

 marbled with yellow, is present in the female, though in a 

 rudimental condition. Again, in certain other lizards, 

 both sexes are equally well provided with throat pouches. 

 Here we see with species belonging to the same group, as 

 in so many previous cases, the same character either con- 

 fined to the males or more largely developed in them than 

 in the females, or again equally developed in both sexes. 

 The little lizards of the genus Draco, which glide through 

 the air on their rib-supported parachutes, and which in the 

 beauty of their colors baffle description, are furnished with 

 skinny appendages to the throat " like the wattles of gall- 

 inaceous birds." These become erected when the animal 



* Stoliczka, * Journal of Asiatic Soc. of Bengal," vol. xxxiv, 1870, 

 p. 166. 



