ON THE BREEDING HABITS, EGGS, AND YOUNG OF CERTAIN 
SNAKES. 
BY 
Ox beans 
Notwithstanding the deep impression which serpents have made on 
the human mind, as shown in literature and in popular conversation, it 
is surprising how little accurate information has been accumulated con- 
cerning some of their habits. The densest ignorance, the result of jin- 
attention and general lack of interest, prevails with regard to some of 
the most interesting matters connected with the life-history of snakes; 
while, on the other hand, many of the popular notions about the powers 
of these animals are either wholly false or are gross exaggerations of 
the truth. The breeding habits of our snakes, even of the most common 
species, belong among the things about which little is known. Hven our 
biologists have given but little attention to this subject, while un- 
scientific people simply recognize the fact that nests of snake eggs are 
occasionally met with. For instance, who would not suppose that all 
the essential facts are known concerning the reproduction of the com- 
mon black-racer, Bascanion constrictor? Nevertheless, where have we 
been told when it lays its eggs, how many there are of them, how they 
are concealed, and when they hatch? 
Some snakes are known to lay eggs which after a period produce 
young. Other snakes are known to retain the eggs within the body 
until the young have attained sufficient size and strength to care for 
themselves after birth. Still other species are supposed sometimes to 
lay eggs; at other times to bring forth living young,* or to produce 
some eges and some living young at the same time.t There are, in- 
deed, oviparous snakes and snakes which are ovoviviparous, and there 
is a conspicuous difference in their eggs. The eggs of the oviparous 
species are furnished with a thick, tough, flexible covering, or “shell,” 
while the eggs of the species which produce living young have cover- 
ings which are very thin and delicate. Now, should such eggs as the 
latter be laid any considerable period before the young are ready to be 
excluded, the thin envelopes would surely be torn during the writhings 
of the embryo. That some of the eggs may be only partially developed 
at the time when the embryos of other eggs are ready to be ushered 
*Proc. A. A. A. S., 1873, p. 185. 
+ Proc. Phil. Acad. Sci., 1887, p. 12.1 
» Proceedings National Museum, Vol. XV, No. 909. 
Proce, N, M, 92——25 385 
