REPTILES. 399 



on the other hand, is blackish-brown, with the belly partly 

 black, while the female is reddish or yellowish-olive, with 

 the belly either uniform yellowish or marbled with black. 

 In the Tragops dispar of the same country the male is 

 bright green and the female bronze colored.* No doubt 

 the colors of some snakes are protective, as shown by the 

 green tints of tree-snakes and the various mottled shades 

 of the species which live in sandy places; but it is doubtful 

 whether the colors of many kinds, for instance of the 

 common English snake a,nd viper, serve to conceal them; 

 and this is still more doubtful with the many foreign 

 species which are colored with extreme elegance. The 

 colors of certain species are very different in the adult and 

 young states. \ 



During the breeding-season the anal scent-glands of 

 snakes are in active function; X and so it is with the same 

 glands in lizards, and as we have seen with the submaxillary 

 glands of crocodiles. As the males of most animals search 

 for the females, these odoriferous glands probably serve to 

 excite or charm the female, rather than to guide her to the 

 spot where the male may be found. Male snakes, though 

 appearing so sluggish, are amorous; for many have been 

 observed crowding round the same female, and even round 

 her dead body. They are not known to fight together from 

 rivalry. Their intellectual powers are higher than might 

 have been anticipated. In the Zoological Gardens they 

 soon learn not to strike at the iron bar with which their 

 cages are cleaned; and Dr. Keen, of Philadelphia, informs 

 me that some snakes which he kept learned after four or 

 five times to avoid a noose, with which they were at first 

 easily caught. An excellent observer in Ceylon, Mr. E. 

 Layard, saw a cobra thrust its head through a narrow hole 

 and swallow a toad. "^With this incumbrance he could 

 not withdraw himself; finding this, he reluctantly dis- 

 gorged the precious morsel, which began to move off; this 



*Dr. A. Gunther, " Reptiles of British India," Ray Soc, 1864, pp. 

 304, 308. 



f Dr. Stoliczka, "Journal of Asiatic Soc. of Bengal," vol. xxxix, 

 1870, pp. 205, 211. 



J Owen, " Anatomy of Vertebrates," vol. i, 1866, p. 615. 



" Rambles in Cevlon," in ' Annals and Ma^. of Nat. Hist.," 2d 

 series, vol. ix, 1852,' p. 333. 



