sely allied to those now living in the same geographical
provinces. Those of Brazil and of Pennsylvania present us with animals
whose nearest analogues are to be found in North and South America, such
as sloths, armadillos and agoutis. Those, again, of Australia present us
with marsupials (_metatheria_) only, allied to, or identical with, those
of that most ancient continent. The extinct forms in each case are
mainly those of the larger animals, which, from their large size, and
low fecundity, would be specially liable to be beaten in the battle for
life by their smaller and more fertile contemporaries, and less likely
to survive those changes in their environment which have undoubtedly
taken place in the long lapse of ages. It is, therefore, certain that
the mammalian life in the Old, New and Australian worlds, was as well
marked out into geographical provinces in the Pleistocene age as at the
present time, and that it has been continuous in these areas from that
remote time to the present day.

_Prehistoric Caves of Neolithic Age in Europe._--The prehistoric caves
are distinguished from Pleistocene by their containing the remains of
domestic animals, and by the wild animals to which they have afforded
shelter belonging to living species. They are divisible into three
groups according to the traces of man which occur in them--into the
Neolithic, Bronze and Iron Ages.

The Neolithic caves are widely spread throughout Europe, and have been
used as the habitations and tombs of the early races who invaded Europe
from the East with their flocks and herds. The first of these
systematically explored was at Perthi Chwareu, near the village of
Llandegla, Denbighshire, in 1869. In the following years five others
were discovered close by, as well as a second group in the neighbourhood
of Cefn on the banks of the Elwy. They contained polished celts, flint
flakes, rude pottery and human skeletons, along with the broken bones of
the pig, dog, horse, Celtic shorthorn and goat. The remains of the wild
animals belong to the wolf, fox, badger, bear, wild boar, stag, roe,
hare and rabbit. Most of the bones were broken or cut, and the whole
group was obviously an accumulation which resulted from these caves
having been used as dwellings. They had subsequently been used for
burial. The human skeletons in them were of all ages, from infancy to
old age; and the interments had been successive until each became
filled. The bodies were buried