RECORD: Darwin, C. R. & Francis Darwin. 1878.07.22-29. Trifolium subterraneum/ Draft of Cross and self fertilisation (several fragments). CUL-DAR209.11.232-236. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 7.2023. RN1
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR209.11 contains material for Darwin's book Movement in plants (1880).
[232]
July 22/ subterraneum Trifolium
Young— Flower head — not fully open (?) or possibly just begun to fade??
standing vertical — stem tied
Roof
[data not transcribed]
(The peduncle did not become more than rectangular with shoot) & flower only at ∟' angle —
(N. B the lifting up of stick & shoot prevented the peduncle from becoming perpendicularly down)
[232v]
[right side of page excised. The text is here combined with that of the excised half in CUL-DAR209.11.233v]
753 (610
Ch XII
Gen Con
cross-fertilisation are transmitted in the case of by plants to the next generation;
and judging from the varieties of the common pea to
many succeeding generations. But this may merely
be that the crossed plants of the first generation are
extremelyvigorous, and that they, transmit their organs like any other character to
their successors.
(Notwithstanding the evil which many plants suffer
from self-fertilisation they can be thus propagated by this means under favourable
conditions for many generations as shown by [illeg] some of my experiments,
and more especially of by the survival during at last
half-a century of the same varieties of the common
pea & sweet-pea, as well probably as of several other
exotic plants which are never or most rarely cross-
-fertilised in this country. But all these plants, as far
as they have been tried, profit greatly by a cross with
a fresh stock. Some few plants, for instance Ophrys
apifera have almost certainly been propagated in a
state of nature for rendered of thousands of
generations without having been once intercrossed
[Cross and self fertilisation, p. 439.]
[233]
subterraneum z
Head withered inclined 36° below Horizon stem tied.
[data not transcribed]
[233v]
[see page 232v above]
[234]
First Flower
On Roof
[data not transcribed] (All used)
[234v]
"a result which is probably effected by mixing the slightly-different physiological units of slightly-different individuals."* (a) But we must not allow this or any other highly generalized view, or the more probable analogy of chemical affinity, to conceal from us our ignorance. We do not know what is the nature or degree of the differentiation in the sexual elements which is favourable for union, and what as in the union case of distinct species, is injurious. We cannot say say why the individuals of certain species profit greatly, and others very little by being crossed. There are some few species which have been self-fertilised for a vast number of generations, and yet are so vigorous that they can compete successfully with a host of surrounding plants. Highly self-fertile varieties
[Cross and self fertilisation, p. 458.]
[235]
First Flower Roof
[data not transcribed] (used)
Tracing IV A
[235v]
act in this manner both with
, parts of Europe, in the U.
& therefore probably in all p
which actually depend on the entire
=ation, the result of holes being bitten in sterile
are capable of fertilizing
there can be no cross-
The extent to which hum
is surprising: a remarka
near Bournemouth, wh
with Erica tetralix grow
walk and every now & then
I had got a handful
[Cross and self fertilisation, p. 426.]
[236]
Monday 29' T. subterraneum (First flower)
[236v]
737 (23
Ch XI
lyx. In these several cases the perforations
ide, but in Antirrhinum majus little
e made on the lower side, close to the
rance which represents a nectary, and
n front of & close to the spot where the
(But the most remarkable case of skill
un to me, is that of of the manner in which perforation of the flowers of Lathyrus sylvestris,
my son Francis* (*Natures Jan 8. 1874
r in this plant is enclose within a tube,
[Cross and self fertilisation, p. 428.]
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 23 August, 2023