he prototype from which
these creatures have arisen, and common sense would lead us to expect that
if any fossils of the ancestors of the modern group of elephants occurred
at all they would be like tapirs. Thus a fossil of much significance in
this connection is _Moeritherium_, whose remains have been found in the
rocks exposed in the Libyan desert, for this creature was practically a
tapir, while at the same time its characters of muzzle and tusk mark it as
very close to the ancestors of the larger woolly elephants of later
geological times, when the trunk had grown considerably and the tusks had
become greatly prolonged. Again the fossil sequence confirms the
conclusions of comparative anatomy, regarding the mode by which certain
modern animals have evolved.

The fossil deer of North America, as well as many other even-toed members
of the group of mammalia possessing hoofs, provide the same kind of
conclusive evidence. The feature of particular interest in the case of
their horns, is a correspondence between the fossil sequence and the order
of events in the life-history of existing species,--that is, between the
results of palaeontology and of embryology. Horns of the earliest known
fossil deer have only two prongs; in the rocks above are remains of deer
with additional prongs, and point after point is added as the ancient
history of deer is traced upwards through the rocks to modern species. We
know that the life-history of a modern species of animals reviews the
ancestral record of the species, and what happens during the development
of deer can be directly compared with the fossil series. It is a matter of
common knowledge that the year-old stag has simple spikes as horns, and
that these are shed to be replaced the following year by larger forked
horns. Every year the horns are lost and new ones grow out, and become
more and more elaborately branched as time goes on, thus giving a series
of developmental stages that faithfully repeats the general order of
fossil horns. Even Agassiz, who was a believer in special creation and an
opponent of evolution, was constrained to point out many other instances,
mainly among the invertebrata, where there was a like correspondence
between the ontogeny of existing species and their phylogenetic history as
revealed by the fossil remains of their ancestors.

* * * * *

In the last place, we must give more than a passing consideration to some
of t