of plants raised from crossed and self-fertilised
flowers. It is really wonderful what an effect pollen from a distinct
seedling plant, which has been exposed to different conditions of life,
has on the offspring in comparison with pollen from the same flower or
from a distinct individual, but which has been long subjected to the
same conditions. The subject bears on the very principle of life, which
seems almost to require changes in the conditions.

LETTER 731. TO G.J. ROMANES.

(731/1. The following extract from a letter to Romanes refers to Francis
Darwin's paper, "Experiments on the Nutrition of Drosera rotundifolia."
"Linn. Soc. Journ." [1878], published 1880, page 17.)

August 9th [1876].

The second point which delights me, seeing that half a score of
botanists throughout Europe have published that the digestion of meat by
plants is of no use to them (a mere pathological phenomenon, as one man
says!), is that Frank has been feeding under exactly similar conditions
a large number of plants of Drosera, and the effect is wonderful. On
the fed side the leaves are much larger, differently coloured, and more
numerous; flower-stalks taller and more numerous, and I believe far
more seed capsules,--but these not yet counted. It is particularly
interesting that the leaves fed on meat contain very many more starch
granules (no doubt owing to more protoplasm being first formed); so that
sections stained with iodine, of fed and unfed leaves, are to the naked
eye of very different colours.

There, I have boasted to my heart's content, and do you do the same, and
tell me what you have been doing.

LETTER 732. TO J.D. HOOKER. Down, October 25th [1876].

If you can put the following request into any one's hands pray do so;
but if not, ignore my request, as I know how busy you are.

I want any and all plants of Hoya examined to see if any imperfect
flowers like the one enclosed can be found, and if so to send them to
me, per post, damp. But I especially want them as young as possible.

They are very curious. I have examined some sent me from Abinger (732/1.
Lord Farrer's house.), but they were a month or two too old, and every
trace of pollen and anthers had disappeared or had never been developed.
Yet a very fine pod with apparently good seed had been formed by one
such flower. (732/2. The seeds did not germinate; see the account of
Hoya carnosa in "Forms of Flowers," page 331.)

LETTER 733. TO G.J. ROMANES.