s Romanes, in the
formation of a new species.

A third great objection was raised against Darwinism. The theory said
that only useful variations were selected by nature. It was asserted
by objectors that the earliest beginnings of any variation must be
too slight to be useful, or as the term went, to have selective value.

It has been noticed by a number of naturalists that certain animals
seem to carry the development of a peculiarity altogether too far. It
is seen for instance that in the Irish Elk, which has for some time
been extinct, the horns were so enormous as to be a source of danger
rather than of assistance to their owner. It was said that the
tendency to produce heavy horns had gained, as it were, a sort of
momentum, and that this impulse had carried the development beyond a
safe limit. The Irish Elk became extinct because his horns were too
heavy. During the Mesozoic period the reptiles grew too large. They
seemed to have carried size to a point at which it became a danger
instead of a help. They completely passed out of existence, leaving
behind them only very much smaller reptiles.

Eimer, of Germany, has based on facts like these his theory of
Orthogenesis. He says that variations in animals are not indefinite
and in every direction, but that they follow along clear and definite
lines. These lines, in the case of the elk and of the Mesozoic
reptiles, developed too far, but ordinarily the effect of such a
tendency is distinctly beneficial to the animal. It particularly
assists in carrying on for a time the variations which have not yet
become useful to the animal. It has always been difficult on Darwinian
principles to understand how the beginnings of the useful variations
could be selected before they were strong enough to be of actual value
to the animal. This tendency to variations in certain directions
instead of at random would account for such early development. This
theory of Orthogenesis has not figured very strongly in the history of
the movement, but it recurs at intervals.

Both in America and France there is a constant tendency on the part of
zooelogists to return to the Lamarckian idea that it is the use of an
organ that develops it, its disuse that makes it fade away. This is
undoubtedly true of the individual, and although Weissman insists that
it is useless to the species as a whole, many zooelogists are slow to
relinquish entirely the idea that somehow these favorable developments
be