protection, there would yet be greater difficulty in transporting them
than the male element, because, being larger than the latter, they are
produced in far smaller numbers. So that many of the lower animals are,
in this respect, analogous with plants. (21. Prof. Sachs ( Lehrbuch der
Botanik, 1870, S. 633) in speaking of the male and female reproductive
cells, remarks, verhalt sich die eine bei der Vereinigung activ,...die
andere erscheint bei der Vereinigung passiv. ) The males of affixed and
aquatic animals having been led to emit their fertilising element in
this way, it is natural that any of their descendants, which rose in
the scale and became locomotive, should retain the same habit; and they
would approach the female as closely as possible, in order not to risk
the loss of the fertilising element in a long passage of it through the
water. With some few of the lower animals, the females alone are fixed,
and the males of these must be the seekers. But it is difficult to
understand why the males of species, of which the progenitors were
primordially free, should invariably have acquired the habit of
approaching the females, instead of being approached by them. But in
all cases, in order that the males should seek efficiently, it would be
necessary that they should be endowed with strong passions; and the
acquirement of such passions would naturally follow from the more eager
leaving a larger number of offspring than the less eager.
The great eagerness of the males has thus indirectly led to their much
more frequently developing secondary sexual characters than the
females. But the development of such characters would be much aided, if
the males were more liable to vary than the females as I concluded they
were after a long study of domesticated animals. Von Nathusius, who has
had very wide experience, is strongly of the same opinion. (22.
Vortrage uber Viehzucht, 1872, p. 63.) Good evidence also in favour
of this conclusion can be produced by a comparison of the two sexes in
mankind. During the Novara Expedition (23. Reise der Novara:
Anthropolog. Theil, 1867, ss. 216-269. The results were calculated by
Dr. Weisbach from measurements made by Drs. K. Scherzer and Schwarz. On
the greater variability of the males of domesticated animals, see my
Variation of Animals and Plants under Domestication, vol. ii. 1868,
p. 75.) a vast number of measurements was made of various parts of the
body in different races, and the men were found in almost every case to
present a greater range of variation than the women; but I shall have
to recur to this subject in a future chapter. Mr. J. Wood (24.
Proceedings of the Royal Society, vol. xvi. July 1868, pp. 519 and
247