CONTRIBUTIONS ON THE LIFE HISTORIES OF 
: CERTAIN SNAKES. 
GEORGE E. BEYER, 
TuLANE UNIVERSITY OF LOUISIANA. 
In reading over the magnificently compiled monograph of the 
poisonous snakes of North America by Mr. Leonhard Stejneger, 
and also an article on the breeding habits of snakes by Dr. 
O. P. Hay, in the Proceedings of the U. S. National Museum 
(Vol. 15, 1892), I find many points of character as well as of 
the reproduction which appear, according to both writers, very 
obscure. 
My observations, extending over a period of nearly twenty 
years, were made principally on ophidians, occurring in central 
Europe, Central America, and our southern states, chiefly 
Louisiana, and were conducted both in nature as well as con- 
finement, the latter especially with a view to note the extent 
of the exceedingly limited mental capacity and the develop- 
ment of their sense organs. I have noted the entire period of 
gestation of at least three of our venomous snakes from the 
time of sexual union to the end of the term, and I dare say 
with comparative certainty that the same length of gestation 
occurs as well in Watrix rigida and Natrix grahamii. 
The term of gestation may vary to a limited number of days, 
but all my notes point to five months and a few days. 
While searching for reptiles in the vicinity of New Orleans 
on the 1oth of March, 1893, I happened to come across a pair 
of Agkistrodon piscivorus in coitu, which must have, evidently, 
been nearly or quite completed, for the male freed itself so 
quickly that I failed to secure it, but the female, an unusually 
large one, became my captive. 
She proved to be a very aggressive and obstinate individual 
for quite a long time, and refused food persistently for fully two 
months. The cage in which I kept her was prepared with 
some imitation of natural surroundings, and after the expira- 
