2 54 Mr. Home’s Observations on the Structure of 
be sufficient to illustrate the general principles upon which such 
varieties depend. 
EXPLANATION OF THE PLATES. 
Tab. XIII. 
A longitudinal section of a grinding tooth of the Asiatic ele- 
phant, in a growing state. The tooth had been previously 
steeped in the muriatic acid, to render it soft, that it might be 
divided with less injury to the tender parts. 
The different processes wffiich compose the tooth are dis- 
tinctly seen, but the enamel which surrounded them was dis- 
solved in the acid ; so that there is a vacant space, between them 
and the bony substance in which they appear to be imbedded. 
The bony substance, which is completely formed along the up- 
per surface of the tooth, is hard and compact ; but the project- 
ing portions, near their termination, are not yet ossified, but are 
in the state of a membrane. 
The cavity of the body of the tooth is filled with a vascular 
pulp, portions of which pass up into the processes, for their 
formation : these are conical in their shape ; so that the pro- 
cesses of the tooth formed upon them, as they become longer, 
have their sides separated more and more, till at last the lower 
edge comes in contact with, and unites to, that of the neigh- 
bouring processes, connecting them together, and forming the 
cavity of the tooth, to which the fangs are afterwards added. 
aaaa. The pulp on which the tooth is formed. 
bbbb . The processes of the tooth, formed upon the pulp. 
