y the remains of an
intermediate formation are intermediate in character.

The inhabitants of each successive period in the world's history have
beaten their predecessors in the race for life, and are, in so far,
higher in the scale of nature; and this may account for that vague yet
ill-defined sentiment, felt by many palaeontologists, that organisation
on the whole has progressed. If it should hereafter be proved that
ancient animals resemble to a certain extent the embryos of more recent
animals of the same class, the fact will be intelligible. The succession
of the same types of structure within the same areas during the later
geological periods ceases to be mysterious, and is simply explained by
inheritance.

If then the geological record be as imperfect as I believe it to be, and
it may at least be asserted that the record cannot be proved to be much
more perfect, the main objections to the theory of natural selection are
greatly diminished or disappear. On the other hand, all the chief laws
of palaeontology plainly proclaim, as it seems to me, that species have
been produced by ordinary generation: old forms having been supplanted
by new and improved forms of life, produced by the laws of variation
still acting round us, and preserved by Natural Selection.

11. GEOGRAPHICAL DISTRIBUTION.

Present distribution cannot be accounted for by differences in physical
conditions. Importance of barriers. Affinity of the productions of the
same continent. Centres of creation. Means of dispersal, by changes of
climate and of the level of the land, and by occasional means. Dispersal
during the Glacial period co-extensive with the world.

In considering the distribution of organic beings over the face of
the globe, the first great fact which strikes us is, that neither the
similarity nor the dissimilarity of the inhabitants of various regions
can be accounted for by their climatal and other physical conditions. Of
late, almost every author who has studied the subject has come to this
conclusion. The case of America alone would almost suffice to prove its
truth: for if we exclude the northern parts where the circumpolar land
is almost continuous, all authors agree that one of the most fundamental
divisions in geographical distribution is that between the New and Old
Worlds; yet if we travel over the vast American continent, from the
central parts of the United States to its extreme southern point, we
meet with the mos