20 THE AMERICAN NATURALIST. [VOL XXXII. 
as I have found repeatedly illustrated in a number of other indi- 
viduals of that species. I did not notice anything unusual 
until late in the evening of September 16, when the female 
(the larger one of the two snakes) brought forth seven young. 
These again were marked and colored like the parents, only 
more brilliantly. I have certainly no reason to doubt the 
negro’s statement, especially as a later dissection proved the 
other snake to have been a male. The term of gestation is in 
this case again five months and four days. On May 3 of the 
same year some students brought me three specimens of 
Natrix grahamii, which they had caught in our university 
grounds. Two of the snakes were females. In September 
five young were born alive, while a sixth one remained dead in 
the membranous eggshell, although it had been expelled from 
the parent’s body. I noticed that the food yolk of these little 
creatures was much larger and remained attached to them 
longer than in the young of the poisonous snakes. 
In regard to Eutenia proxima and E. sirtalis, I am confi- 
dent that, while, of course, the species are ovoviviparous as 
well, the number of young at one time is rarely more than 
eight or nine. Twice I have had young ones of that species 
born in confinement, at one time only five, at another, eight. 
They were five and three-fourths inches in length, and fully 
three-sixteenths of an inch in thickness. As to the term of 
gestation I am not certain, but pairing occurs in March and 
April, for I have had repeated opportunities to observe it in 
our swamps and palmetto thickets. 
The structure of the membranous eggshell of all ovovivip- 
arous snakes seems to be alike; it is very thin and perfectly 
transparent, and causes no difficulty to the young snakes to 
rupture it. The egg tooth, however, I have been able to find 
only in the young of Natrix grahamii. The motion of ruptur- 
ing the inclosing membrane I saw very nicely demonstrated by 
the young of Agkistrodon piscivorus. The vertex lies close to 
the side of the wet and slimy shell; the simple motion of draw- 
ing the tip end of the nose upward and backward suffices to 
make an opening large enough for the little creature to crawl 
forth. All snakes shed skin from three to ten days after 
