the upper jaw in front there is the one huge tusk on
each side, and in the lower jaw no front teeth at all! Then as to the
grinders. In the elephant these are enormous, with many transverse
ridges on the elongated crown, and so big that there is only room for
one at a time in each half of upper and lower jaw. Six of these
succeed one another in each half of each jaw, and correspond (though
greatly altered) to six of the seven grinders of the typical
dentition. Are there amongst older fossil elephants and animals like
elephants any which have an intermediate condition of the teeth,
connecting the extremely peculiar teeth of the modern elephants with
the typical dentition such as is approached by the pig, the dog, the
tapir, and the hedgehog? There are such links. We know a great many
elephants from Pleistocene and Pliocene strata--some from European
localities, more from India, and some from America. A little elephant
not more than 3 feet high when adult is found fossil in the island of
Malta; other species were a little larger than the living African
elephant. Whilst the Indian elephant has as many as twenty-four
cross-ridges on its biggest grinding tooth (Fig. 8) there is a fossil
kind which has only six such ridges. But besides true elephants we
know from the Pliocene, Miocene, and Upper Eocene of the old world,
the remains of elephant-like creatures (some as big as true
elephants), which are distinguished by the name "Mastodon" (Fig. 11).
And, in fact, we are conducted through a series of changes of form by
ancient elephant-like creatures which are of older and older date as
we pass along the series, and are known as (1) Mastodon, (2)
Tetrabelodon, (3) Palaeomastodon, (4) Meritherium, until we come to
something approaching the general form of skull and skeleton and the
typical dentition of the early mammalian ancestor. Mastodons of
several species are found in Pliocene strata in Europe and Asia;
detached teeth are found in Suffolk. One species actually survived
(why, we do not know) in North America into the early human period,
and whole skeletons of it are dug out from the morasses such as that
of "Big-bone Lick." The Mastodons had a longer jaw and face than the
elephants, though closely allied to them. They bring one nearer to
ordinary mammals in that fact, and also in having (when young) two
front teeth or incisors in the lower jaw. Their grinders had the
crowns less elongated than those of the elephants, and ther