400 THE DESCENT OF MAN. 



was too much for snake philosophy to bear, and the toad 

 was again seized, and again was -the snake, after violent 

 efforts to escape, compelled to part with its prey. This 

 time, however, a lesson had been learned, and the toad was 

 seized by one leg, withdrawn, and then swallowed in 

 triumph." 



The keeper in the Zoological Gardens is positive that 

 certain snakes, for .instance Orotalus and Python, distin- 

 guish him from all other persons. Cobras kept together in 

 the same cage apparently feel some attachment toward each 

 other. * 



It does not, however, follow because snakes have some 

 reasoning power, strong passions and mutual affection, 

 that they should likewise be endowed with sufficient taste 

 to admire brilliant colors in their partners, so as to lead to 

 the adornment of the species through sexual selection. 

 Nevertheless, it is difficult to account in any other manner 

 for the extreme beauty of certain species; for instance, of 

 the coral-snakes of South America, which are of a rich red 

 with black and yellow transverse bands. I well remember 

 how much surprise I felt at the beauty of the first coral- 

 snake which I saw gliding across a path in Brazil. Snakes 

 colored in this peculiar manner, as Mr. Wallace states on 

 the authority of Dr. Giinther,f are found nowhere else in 

 the world except in South America, and here no less than 

 four genera occur. One of these, Elaps, is venomous; a 

 second and widely-distinct genus is doubtfully venomous, 

 and the two others are quite harmless. The species belong- 

 ing to these distinct genera inhabit the same districts, and 

 are so like each other that no one "but a naturalist would 

 distinguish tlie harmless from the poisonous kinds." Hence, 

 as Mr. Wallace believes, the innocuous kinds have proba- 

 bly acquired their colors as a protection, on the principle of 

 imitation; for they would naturally be thought dangerous 

 by their enemies. The cause, however, of the bright 

 colors of the venomous Elaps remain to be explained, and 

 this may perhaps be sexual selection. 



Snakes produce other sounds besides hissing. The 

 deadly Ecliis carinata has on its sides some oblique rows of 

 scales of a peculiar structure with serrated edges ; and 



*Dr. Gunther, " Reptiles of British India," 1864, p. 340. 

 f "Westminster Review," July 1, 1867, p. 3^. 



