d
never have obtained any mammals at all.

{420} Now these ancient African mammals are Lemurs, Insectivora, and small
Carnivora, chiefly Viverridae; and all these groups are known to have
inhabited Europe in Eocene and Miocene times; and that the union was with
Europe rather than with America is clearly proved by the fact that even the
insectivorous Centetidae, now confined to Madagascar and the West Indies,
inhabited France in the Lower Miocene period, while the Viverridae, or
civets, which form so important a part of the fauna of Madagascar as well
as of Africa, were abundant in Europe throughout the whole Tertiary period,
but are not known to have ever lived in any part of the American continent.
We here see the application of the principle which we have already fully
proved and illustrated (Chapter IV., p. 60), that all extensive groups have
a wide range at the period of their maximum development; but as they decay
their area of distribution diminishes or breaks up into detached fragments,
which one after another disappear till the group becomes extinct. Those
animal forms which we now find isolated in Madagascar and other remote
portions of the globe all belong to ancient groups which are in a decaying
or nearly extinct condition, while those which are absent from it belong to
more recent and more highly-developed types, which range over extensive and
continuous areas, but have had no opportunity of reaching the more ancient
continental islands.

_Anomalies of Distribution and How to Explain Them._--If these
considerations have any weight, it follows that there is no reason whatever
for supposing any former direct connection between Madagascar and the
Greater Antilles merely because the insectivorous Centetidae now exist only
in these two groups of islands; for we know that the ancestors of this
family must once have had a much wider range, which almost certainly
extended over the great northern continents. We might as reasonably suppose
a land-connection across the Pacific to account for the camels of Asia
having their nearest existing allies in the llamas and alpacas of the
Peruvian Andes, and another between Sumatra and Brazil, in order that the
ancestral tapir of one country might have passed over to the other. In both
{421} these cases we have ample proof of the former wide extension of the
group. Extinct camels of numerous species abounded in North America in
Miocene, Pliocene, and even Post-pliocene times, a