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different Species of Asiatic Elephants. 
applied internally, from the core on which they are formed, 
similar to what happens in the growth of the horns of some ani- 
mals. When the tusks of the living elephant are sawn through, 
and the remaining portion exposed some months to the air, this 
structure is clearly shown. 
If the period in which one of these circular layers is com- 
pleted could be ascertained, this might lead us to fix, with tole- 
rable precision, the age of an elephant, by counting the circles 
in each tusk. 
Cutting off a portion of the tusks of a living elephant, is 
a common practice ; it is done with a view to make the tusks 
grow thicker, when they are too long and slender, and also 
sometimes for the sake of uniformity, when they grow in a 
wrong direction. 
In describing the structure of the grinders, it must be ob- 
served, that a grinder is composed of several distinct laminae or 
teeth, each covered with its proper enamel; and that these 
teeth are merely joined to each other by an intermediate softer 
substance, acting like a cement. I accordingly use the words 
teeth, strata, layers, and laminae, as synonimous, when speak- 
ing of the structure of the grinders. 
The structure of the grinders, even from the first glance, 
must appear very curious, being composed of a number of per- 
pendicular laminae, which may be considered as so many teeth ; 
each covered with a strong enamel, and joined to one another 
by the common osseous matter. This, being much softer than 
the enamel, wears away faster by the mastication of the food ; 
and, in a few months after some of these teeth cut the gum, the 
enamel remains considerably higher, so that the surface of 
each grinder soon acquires a ribbed appearance, as if originally 
mdccxcix. F f 
