Chap. XII. REPTILES. 29 



colour; nor do I know that the males fight together, 

 though this is probable, for some kinds make a prodi- 

 gious display before the females. Bartram ''' describes 

 the male alligator as striving to win the female by 

 splashing and roaring in the midst of a lagoon, " swollen 

 " to an extent ready to burst, with his head and tail 

 " lifted up, he spins or twirls round on the surface of 

 " the water, like an Indian chief rehearsing his feats 

 " of war." During the season of love, a musky odour 

 is emitted by the submaxillary glands of the crocodile, 

 and pervades their haunts.^^ 



Oljhidia. — I have little to say about Snakes. Dr. 

 Giinther informs me that the males are always smaller 

 than the females, and generally have longer and slen- 

 derer tails ; but he knows of no other difference in 

 external structure. In regard to colour, Dr. Giinther 

 can almost always distinguish the male from the female 

 by his more strongly-pronounced tints; thus the black 

 zigzag band on the back of the male English viper is 

 more distinctly defined than in the female. The differ- 

 ence is much plainer in the Kattle-snakes of K. A^i^erica, 

 the male of which, as the keeper in the Zoological 

 Gardens shewed me, can instantly be distinguished from 

 the female by having more lurid yellow about its whole 

 body. In S. Africa the BucejyJialus cajoensis presents an 

 analogous difference, for the female " is never so fully 

 '' variegated with yellow on the sides, as the male." "^^ 

 The male of the Indian Dii^sas mjnodon, on the other 

 hand, is blackish-brown, with the belly partly black, 

 whilst the female is reddish or yellowish-olive with the 

 belly either uniform yellowish or marbled with black. 



^7 ' Travels through Carolina,' &c., 1791, p. 128. 



^'^ Owen, ' Anatomy of Vertebrates,' vol. i. 1866, p. 615. 



*^ Sir Andrew Smith, Zoolog. of S. Africa : Keptilia,' 1840, pi. 



