THUR EGG-TOOTIH OF THE YOUNG SNAKES AND LIZARDS. 
BY DR. D. FL. WEINLAND. 
(With a plate.) 
—_——0- 
In the year 1853, I had an opportunity of studying the 
embryology of the European Ring Snake, ( Zropidonotus 
natriz, Kuhl.) having found, in the beginning of August, some 
four or five dozen of her eggs. I watched the development of the 
embryos, opening the eggs from day today. On the 26th of Aug. 
while looking over the eggs, I was surprised to find, in many of 
them, a long sharp slit through their thick leathery shell, not 
at all torn by the pressing of the embryo from within, as one 
would suppose, but, as I saw clearly enough, cut as if by a 
sharp knife. I took out the embryo and sought for a tubercle 
on the top of the snout, remembering the horny wart of the 
young chicken for the same purpose ; but there was nothing to 
be found. While I was holding the little snake in my hand, it 
scratched my finger, and thus disclosed its cutting istrument 
—a single, very sharp and rather broad tooth, protruding a 
little way, nearly horizontally from the upper jaw (Fig. 1. b.) 
This tooth was about one millimeter (about 4-100 of an inch) 
long, and half as broad, fixed in a socket in the middle of the 
intermaxillary bone, which bears no other tooth. This two 
edged shovel-like knife projected a quarter, sometimes a half of 
a millimeter from the upper jaw, as the diamond of the glazier 
does from its handle. ‘To a shovel it bears the additional 
resemblance of being concave above, convex below. ‘The lower 
convex part is swelled up about the middle, resembling a bowl, 
which makes the odd profile view of the tooth (Fig. 5.) The 
two lower corners of it are generally rounded. Below and on 
the sides, the margin is sharp, cutting and transparent, while 
the thicker centre, containing the pulp of the tooth, is yellowish 
and dark. 1 have made a microscopical preparation of the egg 
