Chap. XII. Reptiles. 353 



It does not, however, follow because snnkes have some 

 reasoning power, strong passions and mutual afl'ection, that they 

 should likewise be endowed with suificient taste to admire 

 brilliant colours in their partners, so as to lead to the adorn- 

 ment of the species through sexual selection. Nevertlieless, it is 

 difficult to account in any other manner for the extreme beauty 

 of certain species ; for instance, of the coral-snakes of S. 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 coloured in this peculiar manner, as Mr. Wallace states 

 on the authority of Dr. Giinther,"^ are found nowhere else 

 iu the world except in S. 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 belonging to these 

 distinct genera inhabit the same districts, and are so like each 

 other, that no one " but a naturalist would distinguish the 

 " harmless from the poisonous kinds." Hence, as Mr. Wallace 

 believes, the innocuous kinds have probably acquired their 

 colours as a protection, on the principle of imitation ; for they 

 would natuially be thought dangerous by their enemies. The 

 cause, however, of the bright colours of the venomous Elaps 

 remains to bo explained, and this may perhaps be sexual 

 selection. 



Snakes produce other sovmds besides hissing. The dendly 

 E<-kisi airinata has on its sides some oblique i:ows of scales of a 

 peculiar structure with serrated edges ; and when this snake is 

 excited, these scales are rubbed against each other, which pro- 

 duces " a curious prolonged, almost hissing sound." "" With 

 respect to the rattling of the rattle-snake, we have at last some 

 definite information : for Professor Aughey states,"* that on two 

 occasions, being himself unseen, he watched from a little distance, 

 a rattle-snake coiled up with head erect, which continued to 

 rattle at short intervals for half an hour : and at last he saw 

 another snake approach, and when they met they paired. 

 Hence he is satisfied that one of the uses of the rattle is to bring 

 the sexes together. Unfortunately he did not ascertain whether 

 jt was the male or the female which remained stationary and 

 called for the otlier. But it by no means follows from the 

 above fact that the rattle may not be of use to those snakes in 

 other ways, as a warning to animals which would otherwise 



""Westminster Review,' July 1st, Snc.' 1871, p. 196. 

 1867, p. 32. "' 'The American N;ituralis(, 



'^ Dr. Anderson, ' Proc. Zoolog. 187.", p. H.'j. 



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