54 VERTEBRATA. REPTILIA. 



pose the rattles."* The genus consists of many 

 species, all of which are exclusively American. The 

 Diamond Rattlesnake (C. Durissus) is found in 

 Guiana, and the Banded (C. Horridus) in the 

 United States ; both are sometimes six feet in 

 length. 



The Rattlesnakes are somewhat dull and inert in 

 their motions, rarely attacking man or the larger 

 animals unless provoked. The warning sound of 

 their rattle is always given some moments before the 

 fatal spring, and as their progression is very slow, 

 accidents rarely occur. Like most other Serpents, 

 they diffuse, when excited, a most fetid odour, which 

 is intolerable. Their usual prey is squirrels, birds, 

 &c. Much has been written of the power of fasci- 

 nation possessed by these reptiles, depriving their 

 intended victim of all power to flee, and even draw- 

 ing them, as if by a resistless influence, into the 

 very jaws of the destroyer. Some writers have at- 

 tempted to explain away a great deal of this attri- 

 buted power, by imputing it to the paralysing effect 

 of fear, to the stupifying power of the odour, &c. ; 

 but still much seems to remain unaccounted for. 

 The poison is not always equally virulent. If the 

 Serpent make several successive attacks at short 

 intervals, it seems that the result becomes much 

 more feeble at every bite, the poison becoming com- 

 paratively exhausted. Mr. Bell records an instance 

 in which three rats were successively introduced into 

 the cage of a Rattlesnake, with very different results. 

 * Vol. v. p. 368. 



