theme in terms of "essences." Naudin, however, does not clearly
distinguish between hybrid and pure gemmules, and makes the assumption
that the hybrid or mixed essences tend constantly to dissociate into
pure parental essences, and thus lead to reversion. It is to this view
that Darwin refers when he says that Naudin's view throws no light on
the reversion to long-lost characters. His own attempt at explaining
this fact occurs in "Variation under Domestication," II., Edition II.,
page 395. Mr. Bateson ("Mendel's Principle of Heredity," Cambridge,
1902, page 38) says: "Naudin clearly enuntiated what we shall henceforth
know as the Mendelian conception of the dissociation of characters of
cross-breds in the formation of the germ-cells, though apparently he
never developed this conception." It is remarkable that, as far as we
know, Darwin never in any way came across Mendel's work. One of Darwin's
correspondents, however, the late Mr. T. Laxton, of Stamford, was close
on the trail of Mendelian principle. Mr. Bateson writes (op. cit., page
181): "Had he [Laxton] with his other gifts combined this penetration
which detects a great principle hidden in the thin mist of 'exceptions,'
we should have been able to claim for him that honour which must ever
be Mendel's in the history of discovery.") The tendency of hybrids
to revert to either parent is part of a wider law (which I am fully
convinced that I can show experimentally), namely, that crossing races
as well as species tends to bring back characters which existed in
progenitors hundreds and thousands of generations ago. Why this should
be so, God knows. But Naudin's view throws no light, that I can see,
on this reversion of long-lost characters. I wish the Ray Society would
translate Gartner's "Bastarderzeugung"; it contains more valuable matter
than all other writers put together, and would do great service
if better known. (664/2. "Versuche uber die Bastarderzeugung im
Pflanzenreich": Stuttgart, 1849.)

LETTER 665. TO T.H. HUXLEY.

(665/1. Mr. Huxley had doubted the accuracy of observations on Catasetum
published in the "Fertilisation of Orchids." In what formed the
postscript to the following letter, Darwin wrote: "I have had more
Catasetums,--all right, you audacious 'caviller.'")

Down, October 31st [1862].

In a little book, just published, called the "Three Barriers" (a
theological hash of old abuse of me), Owen gives to the author a new
resume of his brain doc