iberty which I
take in returning you the postage stamps. I never heard of such a scheme
as that you were compelled to practise to fertilise the Gongora! (642/1.
See "Fertilisation of Orchids," Edition, II., page 169. "Mr. Scott tried
repeatedly, but in vain, to force the pollen-masses into the stigma of
Gongora atro-purpurea and truncata; but he readily fertilised them by
cutting off the clinandrum and placing pollen-masses on the now exposed
stigma.") It is a most curious problem what plan Nature follows in this
genus and Acropera. (642/2. In the "Fertilisation of Orchids," Edition
II., page 169, Darwin speculates as to the possible fertilisation of
Acropera by an insect with pollen-masses adhering to the extremity of
its abdomen. It would appear that this guess (which does not occur in
the first edition) was made before he heard of Cruger's observation on
the allied genus Gongora, which is visited by a bee with a long tongue,
which projects, when not in use, beyond and above the tip of the
abdomen. Cruger believes that this tongue is the pollinating agent.
Cruger's account is in the "Journal of the Linn. Soc." VIII., 1865,
page 130.) Some day I will try and estimate how many seeds there are in
Gongora. I suppose and hope you have kept notes on all your observations
on orchids, for, with my broken health and many other subjects, I do not
know whether I shall ever have time to publish again; though I have a
large collection of notes and facts ready. I think you show your wisdom
in not wishing to publish too soon; a young author who publishes every
trifle gets, sometimes unjustly, to be disregarded. I do not pretend
to be much of a judge; but I can conscientiously say that I have never
written one word to you on the merit of your letters that I do not fully
believe in. Please remember that I should very much wish for a copy of
your paper on sterility of individual orchids (642/3. "On the Individual
Sterility and Cross-Impregnation of Certain Species of Oncidium." [Read
June 2nd, 1864.] "Linn. Soc. Journal," VIII., 1865. This paper gives a
full account of the self-sterility of Oncidium in cases where the pollen
was efficient in fertilising other individuals of the same species and
of distinct species. Some of the facts were given in Scott's paper,
"Experiments on the Fertilisation of Orchids in the Royal Botanic Garden
of Edinburgh," published in the "Proc. Bot. Soc. Edinb." 1863. It
is probably to the latter paper that Dar