262 USE OF THE RATTLES OF THE RATTLESNAKE. 
- We are not to judge of the advantage or disadvantage of the 
rattles by their effect upon the nerves of man alone, though no 
doubt many a man has turned his back and been deterred from 
making an attack by the sound of these rattles and the defiant 
attitude of their possessor. 
The ability of the snake to defend itself does not consist in its 
strength or size, or in its power of overcoming its adversary by 
a prolonged conflict, for most of its enemies are its superior in 
size and strength. Nor does its deadly poison act quickly 
enough to secure its own safety when it is attacked, but, in most 
cases, the victim, after the deadly stroke is given may still revenge 
itself by the destruction of the snake. But the certainty of the 
effect of the poison serves as a warning and is advantageous, not 
in defense after the attack is made, but in preventing an attack — 
from being made. If, then, the color of the rattlesnake ba 
different from all harmless snakes, so much so as to render it : 
conspicuous, this would be beneficial to it, by the readiness with : 
which all animals would recognize it, and thus protect the snake 
by this notice of the deadly character of its weapons. Jf thena 
conspicuous color would be of advantage, it seems to me that ead 
other means which it may be able to use in making know? a 
character to any animal that may come near it, would be advat 
tion, and that the whirring noise which it produc 
of the matter, admirably serves its purpose. 
language, “I am a rattlesnake, armed with what will 
you if you come too near ; give me a wide berth !” 33 t0 
Prof. Shaler remarks that it is a fact well known eer 
those who have observed serpents, that many when in as ae 
excitement vibrate the end of their tail just as the m je 
oes. This statement reminded me of a South American% 
st” (vol. bP 
described by Darwin in his “‘ Voyage of a Naturali 
123, Harper’s ed.), where he says :— 
= “Of reptiles there are many kinds: one snake ee na 
cephalus, or Cophias), from the size of the poison 
other naturalists, makes this a sub-genus 
intermediate between it and the viper. In ¢ 
opinion I observed a fact, which appears to me ve 
ean : “en though it ® 
instructive, as showing how every character, even : 
