truded, and, what is very odd, they
certainly seemed to have penetrated the coats of the ovules, but in
no one instance the foramen of the ovule!! I mention this because
it directly bears on your explanation of Dr. Cruger's case. (640/3.
Cruger's case here referred to is doubtless the cleistogamic
fertilisation of Epidendrum, etc. Scott discusses the question of
self-fertilisation at great length in a letter to Darwin dated April,
and obviously written in 1863. In Epidendrum he observed a viscid matter
extending from the stigmatic chamber to the anther: pollen-tubes had
protruded from the anther not only where it was in contact with the
viscid matter, but also from the central part, and these spread "over
the anterior surface of the rostellum downward into the stigma." Cruger
believed the viscid matter reaching the anther was a necessary condition
for the germination of the pollen-grains. Scott points out that the
viscid matter is produced in large quantity only after the pollen-grains
have penetrated the stigma, and that it is, in fact, a consequence, not
a preliminary to fertilisation. He finally explains Cruger's case thus:
"The greater humidity and equability of temperature consequent on
such conditions [i.e. on the flowers being closed] is, I believe, the
probable cause of these abnormally conditioned flowers so frequently
fertilising themselves." Scott also calls attention to the danger
of being deceived by fungal hyphae in observations on germination of
pollen.) I believe that your explanation is right; I should never have
thought of it; yet this was stupid of me, for I remember thinking that
the almost closed imperfect flowers of Viola and Oxalis were related
to the protrusion of the pollen-tubes. My case of the Aceras with the
aborted labellum squeezed against stigma supports your view. (640/4. See
"Fertilisation of Orchids," Edition II., page 258: the pollen germinated
within the anther of a monstrous flower.) Dr. Cruger's notion about the
ants was a simple conjecture. About cryptogamic filaments, remember Dr.
C. says that the unopened flowers habitually set fruit. I think that you
will change your views on the imperfect flowers of Viola and Oxalis...

LETTER 641. (?)

LETTER 642. TO J. SCOTT. May 2nd [1863].

I have left home for a fortnight to see if I can, with little hope,
improve my health. The parcel of orchid pods, which you have so kindly
sent me, has followed me. I am sure you will forgive the l