ore hardly ever cross. When
artificially crossed by removal of own pollen in bud, the offspring are
very vigorous.

Farewell.--I wish I could compel you to go on working at fertilisation
instead of so insignificant a subject as the commerce of the country!

You pay me a very pretty compliment at the beginning of your paper.

LETTER 710. TO J.D. HOOKER.

(710/1. The following letters to Sir J.D. Hooker and the late Mr.
Moggridge refer to Moggridge's observation that seeds stored in the nest
of the ant Atta at Mentone do not germinate, though they are certainly
not dead. Moggridge's observations are given in his book, "Harvesting
Ants and Trap-Door Spiders," 1873, which is full of interesting details.
The book is moreover remarkable in having resuscitated our knowledge of
the existence of the seed-storing habit. Mr. Moggridge points out that
the ancients were familiar with the facts, and quotes the well-known
fable of the ant and the grasshopper, which La Fontaine borrowed from
Aesop. Mr. Moggridge (page 5) goes on: "So long as Europe was taught
Natural History by southern writers the belief prevailed; but no sooner
did the tide begin to turn, and the current of information to flood from
north to south, than the story became discredited."

In Moggridge's "supplement" on the same subject, published in 1874, the
author gives an account of his experiments made at Darwin's suggestion,
and concludes (page 174) that "the vapour of formic acid is incapable
of rendering the seeds dormant after the manner of the ants," and
that indeed "its influence is always injurious to the seeds, even when
present only in excessively minute quantities." Though unable to explain
the method employed, he was convinced "that the non-germination of the
seeds is due to some direct influence voluntarily exercised by the ants,
and not merely to the conditions found in the nest" (page 172). See
Volume I., Letter 251.)

Down, February 21st [1873].

You have given me exactly the information which I wanted.

Geniuses jump. I have just procured formic acid to try whether its
vapour or minute drops will delay germination of fresh seeds; trying
others at same time for comparison. But I shall not be able to try them
till middle of April, as my despotic wife insists on taking a house in
London for a month from the middle of March.

I am glad to hear of the Primer (710/2. "Botany" (Macmillan's Science
Primers).); it is not at all, I think, a folly. D