01^ THE POISON-FANGS IN SERPENTS. 417 
will generally be found a rudimentary fang, so small, that 
it is nearly of the same form and structure as one of the 
common palatine or maxillary teeth ; that is, it is composed 
of a horny substance, or enamel, and has a single cavity, 
in which is contained the nourishing pulp, or model, as it 
were, of the tooth* The tooth itself is exceedingly soft. 
The rudimentary fang, which we shall consider as next in 
succession, because next in size, has already assumed a dif- 
ferent appearance. At its base may be seen a part of the 
anterior opening, or that through which the poisonous 
fluid is afterwards to pass : this little cavity or opening al- 
ready contains a pulp. The third tooth, reckoning always 
by the increasing size, shews a much more complex struc- 
ture, for the tooth growing continually from its base, the 
anterior opening is entirely formed. The external and 
convex cortex of the tooth has become consolidated imme^ 
diately behind the opening ; but near the base a line may 
readily be perceived, extending to the soft parts at the base 
of the tooth itself. This line, in some teeth, strongly re^ 
sembles a fissure ; but I have never found it to be really 
so, in the rattle-snake, or in the fangs of those serpents 
which, by reason of their size, could be easily examined. 
It is not improbable that, during the very early and soft 
state of the tooth, it may be partly open. As the tooth 
grows, the enamel on its convex external surface closes 
constantly behind the anterior opening, and advances gra- 
dually towards its base; whilst, at the same time, there 
arises a firm, horny, or osseous laminaj which, proceeding 
from the convex surface of the poison-canal, divides the 
external cavity, or that containing the nourishing pulp of 
the tooth, at this point, and, indeed, throughout its whole 
length, into two equal parts. A section, therefore, of a 
tooth, at this stage of growth, will present a variety of ap- 
pearances, depending on the situation of the section. If 
VOL. V. D d 
