388 SNAKES. 



or not. Stealthily and slowly it approaches its head, but 

 on the slightest movement of the little animal, recedes in 

 alarm, and is some time before it makes a second venture. 

 I have seen a rattlesnake thus timidly advancing and 

 recoiling three or four times before it has the courage to 

 give the fatal stroke. Even after the bite it watches its 

 victim with a steadiness in which terror is the strongest 

 expression ; and when the rat has remained motionless for 

 a time, and the rattlesnake ventures near to investigate 

 and make sure it is dead, one faint gasp or dying struggle 

 will cause the reptile to dart back in excessive alarm, and 

 wait again some minutes before venturing near. After long 

 and patient observations, I am still doubtful whether 

 stupidity or timidity predominates in viperine natures. 



Of the other well-known and formidable American 

 Crotalidcs is the ^ Fer de lance^ {Trigonocephaltis lanceolatiis) 

 of the Antilles and Central America. This has also a 

 pointed tail. The Jararaca of Gray {Grasped ocephaliis 

 Braziliensis) is another, but without the point. Of the true 

 rattlesnakes, Dumeril gave five genera in 1844, viz. Crotalo- 

 phorus, Crotalus, Catidisona, UrocrotaloJi, and UrosopJiits. 



From the two species originally known, we see how 

 they have gradually multiplied as the country has been 

 more thoroughly explored. In i860. Dr. Weir Mitchel 

 affirmed that twenty species had been then described ; 

 probably the most recent ' Reports ' or Bulletins will 

 tell us of yet others. And these latter are exclusive of the 

 non-rattle-bearing CrotalidcB. 



Dr. Mitchel's experiments were with the northern species, 

 xhicfly Cro. durissus ; and as a relief from this wearisome 



