380 
MAMMALIA OF INDIA. 
Hyracoidea, the conies ; and the rest come under. Ungulata. Apparently 
singular as is the elephant in its anatomy, it bears traces of affinity to 
Side view of Grinders of Asiatic 
Elephant. 
both Rodentia and Ungulata. The 
composition of its massive tusks or 
incisors, and also of its grinders, re- 
sembles that of the Rodents. The 
tusks grow from a persistent pulp, 
which forms new ivory coated with 
enamel, but the grinders are composed 
of a number of transverse perpendicu- 
lar plates, or vertical laminz of dentine, 
enveloped with enamel, cemented to- 
gether by layers of a substance called 
cortical, The enamel, by its superior 
hardness, is less liable to attrition, and, 
standing above the rest, causes an un- 
even grinding surface. Each of these 
plates is joined at the base of the tooth, 
and on the grinding surface the pattern 
formed by them distinguishes at once 
the Indian from the African elephant. 
In the former, the transverse ridges are 
in narrow, undulating loops, but in the 
African they form decided lozenges. 
These teeth, when worn out, are suc- 
ceeded by others pushing forward from 
behind, and not forced up vertically, as in the case of ordinary deciduous 
one and sometimes two 
grinders on each side, ac- 
cording to age. In the wild 
state sand and grit, entangled 
in the roots of plants, help 
in the work of attrition, and, 
according to Professor W. 
Boyd Dawkins, the tame 
animal, getting cleaner food, 
‘and not having such wear 
and tear of teeth, gets a de- 
formity by the piling over of 
the plates of which the grin- 
der is composed. An in- 
stance of this has come under my notice. 
teeth, so that it occasionally happens that the elephant has sometimes 
An elephant belonging to 
my brother-in-law, Colonel W. B. Thomson, then Deputy Commissioner 
