the Teeth of graminivorous Quadrupeds. 241 
rations it was found, that the processes of the tooth, which 
may be called ivory, were all formed upon so many portions of 
one common pulp, which had its origin in the jaw; and that the 
intermediate substance, which may be called bone, was formed 
upon a species of ligament situated immediately under the gum, 
from which, membranous elongations extended into the spaces 
between the processes of the tooth. 
As this is a subject not favourable for minute description, the 
annexed drawings will give a more satisfactory idea of what is 
meant to be described, than can readily be done in words. 
In these drawings is represented the ligamentous substance, 
with its projecting membranes ; and the vascular pulps ; also 
the mode in which the ossification takes place in the one, and 
the formation of the substance of the tooth in the other. 
This structure of tooth is not peculiar to the elephant, but 
common to the teeth of all animals whose food requires to be 
ground, or much bruised, before it is swallowed. 
In the elephant's tooth, from the largeness of its size, the 
parts are more distinct, and more readily contrasted with each 
other ; but, in other animals, even those of a small size, as the 
sheep, the different structures are readily detected. 
It is singular that this structure should have escaped the ac- 
curate investigation of the late Mr. Hunter ; particularly as the 
formation of the teeth was one of the first objects he employed 
himself upon ; and he continued to pursue it to the end of his 
life, marking the varieties which occur in different animals. 
The cause of his overlooking it was the following : in making 
preparations of horses' teeth, to show the figured appearance on 
the grinding surface, he rendered them black by means of fire, 
\vhich did not affect the enamel, so that the white lines of the 
