gh the
micropyle, was first fully demonstrated by Treub in his paper "Sur les
Casuarinees et leur place dans le Systeme naturel," published in the
"Ann. Jard. Bot. Buitenzorg," X., 1891. Two years later Miss Benson gave
an account of a similar phenomenon in certain Amentiferae ("Trans. Linn.
Soc." 1888-94, page 409). This chalazogamic method of fertilisation has
since been recognised in other flowering plants, but not, so far as we
are aware, in the genus Primula.)

It is a shame to trouble [you], but will you tell me whether the ovule
of Primula is "anatropal," nearly as figured by Gray, page 123, "Lessons
in Botany," or rather more tending to "amphitropal"? I never looked at
such a point before. Why I am curious to know is because I put pollen
into the ovarium of monstrous primroses, and now, after sixteen days,
and not before (the length of time agrees with slowness of natural
impregnation), I find abundance of pollen-tubes emitted, which cling
firmly to the ovules, and, I think I may confidently state, penetrate
the ovule. But here is an odd thing: they never once enter at (what I
suppose to be) the "orifice," but generally at the chalaza...Do you
know how pollen-tubes go naturally in Primula? Do they run down walls
of ovarium, and then turn up the placenta, and so debouch near the
"orifices" of the ovules?

If you thought it worth while to examine ovules, I would see if there
are more monstrous flowers, and put pollen into the ovarium, and send
you the flowers in fourteen or fifteen days afterwards. But it is rather
troublesome. I would not do it unless you cared to examine the ovules.
Like a foolish and idle man, I have wasted a whole morning over them...

In two ovules there was an odd appearance, as if the outer coat of ovule
at the chalaza end (if I understand the ovule) had naturally opened or
withered where most of the pollen-tubes seemed to penetrate, which made
me at first think this was a widely open foramen. I wonder whether the
ovules could be thus fertilised?

LETTER 659. TO D. OLIVER. Down [April, 1863].

Many thanks about the Primula. I see that I was pretty right about the
ovules. I have been thinking that the apparent opening at the chalaza
end must have been withering or perhaps gnawing by some very minute
insects, as the ovarium is open at the upper end. If I have time I will
have another look at pollen-tubes, as, from what you say, they ought
to find their way to the micropyle. But ovules