THE RATTLESNAKE AND NATURAL SELECTION. 33 
count for its existence by supposing that it was used as a sex- 
ual call and had been brought up by natural or sexual selection 
for some such office. The burrowing habits of the serpents would 
seem to make sexual calls almost unnecessary and there is no evi- 
dence to make a reasonable basis for belief that rattlesnakes 
exercise any such choice in pairing as would lead to the develop- 
ment of this very singular appendage. Last summer, however, I 
had a long desired opportunity of examining a little into the 
habits of the rattlesnake and obtained some results which have 
served to shake my confidence in the opinions I had held as to the 
usefulness of his rattle. The observations are, as it will be seen, 
rather insufficient for a determination of the points in question, 
but it may be long before I am able to add to them, so I give 
them now hoping that some one with better opportunities for 
studying the ways of this interesting creature may either confirm 
my opinion or refute it. 
The first and only living and active rattlesnake which I met on 
a carriage journey of some months’ duration made during the past 
summer through that part of the Appalachian chain where these 
serpents most abound was in the middle of a road near the Kishi- 
coquillas Valley, Pennsylvania. As the sound of my carriage 
disturbed the surly fellow in his pleasant basking place in the 
_ dusty way, he begun to sound his warning when we were over a 
hundred feet from him. Although quite accustomed to the sound, 
having had specimens captive for months at a time, I mistook it 
for that made by our “locust,” the Cicada rimosa Say, nor did I 
perceive the error until my companion, Mr. A. R. Crandall, called 
my attention to the serpent when we were within forty feet of it. 
My wife and child, a little girl of eight years, who were in the 
carriage also mistook the noise for that made by the Cicada, which 
was abundantly familiar as it had been for a long time the 
most accustomed sound heard while we were travelling through the 
wooded mountain country. 
I have found that the note of the rattlesnake is recognized 
by many persons as indistinguishable from the sound made by the 
Cicada. Professor Brewer, whose long experience in the service of 
the California Geological Survey gave him quite unrivalled op- — 
portunities for becoming familiar with the sound made by this 
reptile, tells me that he was on one occasion at least in great dan- 
ger of being bitten by one of these animals on account of having 
R. NATURALIST, VOL. VI 3 
