ain all that can be said of
it. Nevertheless, a few months suffices to develop the one out of the
other, and that too by a series of modifications so small, that were
the embryo examined at successive minutes, not even a microscope would
disclose any sensible changes. That the uneducated and ill-educated
should think the hypothesis that all races of beings, man inclusive, may
in process of time have been evolved from the simplest monad a ludicrous
one is not to be wondered at. But for the physiologist, who knows that
every individual being _is_ so evolved--who knows further that in their
earliest condition the germs of all plants and animals whatsoever are so
similar, 'that there is no appreciable distinction among them which
would enable it to be determined whether a particular molecule is the
germ of a conferva or of an oak, of a zoophyte or of a man'[332]--for
him to make a difficulty of the matter is inexcusable. Surely, if a
single structureless cell may, when subjected to certain influences,
become a man in the space of twenty years, there is nothing absurd in
the hypothesis that under certain other influences a cell may, in the
course of millions of years, give origin to the human race. The two
processes are generically the same, and differ only in length and
complexity."

* * * * *

The very important extract from Professor Hering's lecture should
perhaps have been placed here. The reader will, however, find it on page
199.

FOOTNOTES:

[321] 'Origin of Species,' Hist. Sketch, p. xvi.

[322] See 'Naval Timber and Arboriculture,' by Patrick Matthew,
published by Adam and C. Black, Edinburgh, and Longmans and Co., London,
1831, pp. 364, 365, 381-388, and also 106-108, 'Gardeners' Chronicle,'
April 7, 1860.

[323] 'Vie et Doctrine Scientifique de Geoffroy Etienne St. Hilaire,'
Paris, Strasbourg, 1847, pp. 344-346.

[324] 'Hist. Nat. Gen.,' tom. ii. 413.

[325] 'Hist. Nat. Gen.,' tom. ii. p. 415.

[326] Ibid.

[327] Ibid. p. 421.

[328] 'Hist. Nat. Gen.,' vol. ii. p. 431, 1859.

[329] 'Origin of Species,' Hist. Sketch, p. xix.

[330] 'Hist. Nat. Gen.,' vol. ii. p. 432.

[331] See 'The Leader,' March 20, 1852, "The Haythorne Papers."

[332] Carpenter's 'Principles of Physiology', 3rd ed., p. 867.

CHAPTER XIX.

MAIN POINTS OF AGREEMENT AND OF DIFFERENCE BETWEEN THE OLD AND NEW
THEORIES OF EVOLUTION.

Having put before the reader with some fulness the theories of t