GENEKATION OF BOA. 
323 
they knew that this Boa produced its young from 
eggs. 
Is this to be received as a case of Snakes that 
retire upon alarm into the mouth and stomach of the 
parent ? It is stated of the Rattlesnake in Hunter’s 
‘ Memoirs of a Captivity among the North American 
Indians,’ that ‘ when alarmed, the young ones, which 
are generally eight or ten in number, retreat into 
the mouth of the parent, and reappear on its giving 
a contractile muscular token that the danger is 
past.’ Credible eye-witnesses say the same of the 
European Viper. (See Charlesworth’s Mag. Nat. 
Hist. vol. i. new series, 1837. p. 441.)” 
In a recent communication to me, Mr. Hill de- 
scribes the Yellow Snake as viviparous, on the au- 
thority of a young friend studious of natural history. 
A gravid female of this species, taken by him, brought 
forth, after some days, eleven young Yellow Snakes. 
If there was no error in the observation of this case, 
it must be considered as an aberration of habit. The 
generation of the BoadcB is well known to be ovi- 
parous, and the fact above mentioned as having fallen 
under my own notice, proves that, sometimes at least, 
our Chilahothrus produces eggs. Is it possible that 
a Serpent, normally oviparous, might retain the eggs 
within the oviduct until the birth of the young, 
when circumstances were not propitious for their 
deposition ? 
The scaly armour of this Serpent does not protect 
it from the attacks of parasitic insects. I found one 
infested by a flat Tick (Ixodes) ^ in some numbers. 
