234 THE TOWER MENAGERIE. 
hending all those in which the poison-fangs are wanting, 
and which are consequently dangerous only in propor- 
tion to the extent of their muscular force; and the other 
consisting of those in which the fangs are present, and 
the bite of which is accompanied with the pouring out of 
a venomous secretion. At the head of the first of these 
divisions rank the Boas, which in the Linnean arrange- 
ment comprehended all those snakes, whether venomous 
or not, whose under surface was covered with narrow 
transverse plates, and whose tail was destitute of rattle. 
Later zoologists have, however, confined that appellation 
to those among the Linnean Boas, which are without 
poisonous fangs and have claws near the vent, and have 
regarded as a distinct genus the snakes which in addition 
to these latter characters have the scales of the under 
surface of the tail so arranged as to form two distinct 
rows. To the latter, which inhabit the Old Continent 
exclusively (while the former are all of them natives of 
America), they have assigned the name of Python. 
The present species, which is commonly exhibited 
under the popular but erroneous title of the Boa Con- 
strictor, appears to be the Pedda Poda of Dr. Russell’s 
Indian Serpents. It is said by that writer to attain a 
length of eight or ten feet; but living specimens have 
been brought to this country of twice that size, and 
some of those now in the Tower are fifteen or sixteen 
feet long. The number of transverse plates on the under 
surface of the body is stated to be two hundred and 
fifty-two, and that of the pairs of scales beneath the tail 
sixty-two. The back is elegantly marked with a series 
of large irregular brown blotches bordered with black ; 
and numerous smaller spots are scattered along the 
