ved whilst the sea was peopled
with most of its present inhabitants; and we have confirmed that
remarkable law so often insisted on by Mr. Lyell, namely, that the
"longevity of the species in the mammalia is upon the whole
inferior to that of the testacea." (5/3. "Principles of Geology"
volume 4 page 40.)

The great size of the bones of the Megatheroid animals, including
the Megatherium, Megalonyx, Scelidotherium, and Mylodon, is truly
wonderful. The habits of life of these animals were a complete
puzzle to naturalists, until Professor Owen solved the problem with
remarkable ingenuity. (5/4. This theory was first developed in the
"Zoology of the Voyage of the 'Beagle,'" and subsequently in
Professor Owen's "Memoir on Mylodon robustus.") The teeth indicate,
by their simple structure, that these Megatheroid animals lived on
vegetable food, and probably on the leaves and small twigs of
trees; their ponderous forms and great strong curved claws seem so
little adapted for locomotion, that some eminent naturalists have
actually believed that, like the sloths, to which they are
intimately related, they subsisted by climbing back downwards on
trees, and feeding on the leaves. It was a bold, not to say
preposterous, idea to conceive even antediluvian trees, with
branches strong enough to bear animals as large as elephants.
Professor Owen, with far more probability, believes that, instead
of climbing on the trees, they pulled the branches down to them,
and tore up the smaller ones by the roots, and so fed on the
leaves. The colossal breadth and weight of their hinder quarters,
which can hardly be imagined without having been seen, become, on
this view, of obvious service, instead of being an encumbrance:
their apparent clumsiness disappears. With their great tails and
their huge heels firmly fixed like a tripod on the ground, they
could freely exert the full force of their most powerful arms and
great claws. Strongly rooted, indeed, must that tree have been,
which could have resisted such force! The Mylodon, moreover, was
furnished with a long extensile tongue like that of the giraffe,
which, by one of those beautiful provisions of nature, thus reaches
with the aid of its long neck its leafy food. I may remark, that in
Abyssinia the elephant, according to Bruce, when it cannot reach
with its proboscis the branches, deeply scores with its tusks the
trunk of the tree, up and down and all round, till it is
sufficiently weakened t