with enamel, cemented together 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 uneven 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 succeeded by others
pushing forward from behind, and not forced up vertically, as in the
case of ordinary deciduous teeth, so that it occasionally happens that
the elephant has sometimes one and sometimes two grinders on each side,
according 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 deformity by the piling
over of the plates of which the grinder is composed. An instance of
this has come under my notice. An elephant belonging to my
brother-in-law, Colonel W. B. Thomson, then Deputy Commissioner of
Seonee, suffered from an aggravated type of this malformation. He
was relieved by an ingenious mahout, who managed to saw off the
projecting portion of the tooth, which now forms a paper-weight. In
my account of Seonee I have given a detailed description of the mode
in which the operation was effected.

[Illustration: Side view of Grinders of Asiatic Elephant.]

[Illustration: Grinder of Asiatic Elephant.]

[Illustration: Grinder of African Elephant.]

[Illustration: Section of Elephant's Skull.]

The skull of the elephant possesses many striking features quite
different from any other animal. The brain in bulk does not greatly
exceed that of a man, therefore the rest of the enormous head is
formed of cellular bone, affording a large space for the attachment
of the powerful muscles of the trunk, and at the same time combining
lightness with strength. This cellular bone grows with the animal,
and is in great measure absent at birth. In the young elephant the
brain nearly fills the head, and the brain-case increases but little
in size during growth, but the cellular portion progresses rapidly
with the growth of the animal, and is piled up over the frontals for
a considerable height, giving the appearance of a bo