; and he speaks as if the sexes
were separate in some and that others were hermaphrodites (639/5.
Cruger ("Linn. Soc. Journal," VIII., page 127) says that the apparently
hermaphrodite form is always sterile in Trinidad. Darwin modified
his account in the second edition of the orchid book.); but I cannot
understand what he means. He has seen lots of great humble-bees buzzing
about the flowers with the pollinia sticking to their backs! Happy man!!
I have the promise, but not yet surety, of some curious results with
my homomorphic seedling cowslips: these have not followed the rule of
Chinese Primula; homomorphic seedlings from short-styled parent have
presented both forms, which disgusts me.

You will see that I am better; but still I greatly fear that I must have
a compulsory holiday. With sincere thanks and hearty admiration at your
powers of observation...

My poor P. scotica looks very sick which you so kindly sent me. (639/6.
Sent by Scott, January 6th, 1863.)

LETTER 640. TO J. SCOTT. April 12th [1863].

I really hardly know how to thank you enough for your very interesting
letter. I shall certainly use all the facts which you have given me (in
a condensed form) on the sterility of orchids in the work which I am now
slowly preparing for publication. But why do you not publish these facts
in a separate little paper? (640/1. See Letter 642, note, for reference
to Scott's paper.) They seem to me well worth it, and you really ought
to get your name known. I could equally well use them in my book. I
earnestly hope that you will experiment on Passiflora, and let me give
your results. Dr. A. Gray's observations were made loosely; he said in
a letter he would attend this summer further to the case, which clearly
surprised him much. I will say nothing about the rostellum, stigmatic
utriculi, fertility of Acropera and Catasetum, for I am completely
bewildered: it will rest with you to settle these points by your
excellent observations and experiments. I must own I never could help
doubting Dr. Hooker's case of the poppy. You may like to hear what I
have seen this morning: I found (640/2. See Letter 658.) a primrose
plant with flowers having three pistils, which when pulled asunder,
without any tearing, allowed pollen to be placed on ovules. This I did
with three flowers--pollen-tubes did not protrude after several days.
But this day, the sixteenth (N.B.--primulas seem naturally slowly
fertilised), I found many tubes pro