76 AUDUBON, THE NATURALIST 



at them and the rump of the animal, until its jaws became so 

 expanded, that, after this, it swallowed the whole remaining 

 parts with apparent ease. 



Audubon then described the appearance that the 

 snake presently assumed, which suggested "a rouleau 

 of money, brought from both ends of a purse towards 

 its centre," and its ineffectual attempts to move off; 

 "when having cut a twig," he continued, "I went up to 

 it, and tapped it on the head, which it raised, as well as 

 its tail, and began for the first time to rattle." 



Now every careful reader of this remarkable story, 

 provided he is at all conversant with the habits of snakes, 

 will perceive that it could not possibly have been invent- 

 ed, for it is strictly and minutely in accord with facts, 

 except in one important particular ; the snake whose be- 

 havior Audubon watched and so accurately described 

 was not the rattlesnake, but the blue racer or black snake 

 (Bascanion constrictor) ; substitute "blue racer," for 

 "rattlesnake," and this record is photographically cor- 

 rect. 8 The black snake does all the things which are 

 here so minutely described — pursuing its prey with as- 

 tounding agility, constricting about it as a prelude to 

 swallowing it, ascending trees readily, coiling when 

 brought to bay as if about to strike, and even vibrating 

 the tip of its tail on the ground or leaves, as if in emu- 

 lation of the genuine rattler, a kind of behavior which 

 was looked upon by Darwin as a case of protective mim- 

 icry. No one could have known the rattlesnake better 

 than Audubon from his constant encounters with it in 

 the field; he made drawings of it, dissected its poison 

 apparatus, and had kept it for months in confinement in 



8 This was very clearly pointed out in 1908 in an excellent article by 

 Mr. George W. Colles, entitled "A Defence of Audubon" (Bibl. No. 160), 

 in Scientific American, vol. xcviii, p. 311. 



