ume II., page 83. The point is that the white and yellow
flowered plants which occur in two species of Verbascum are undoubted
varieties, yet "the sterility which results from the crossing of the
differently coloured varieties of the same species is fully as great as
that which occurs in many cases when distinct species are crossed."

The sterility of the long-styled form (B) of Linum grandiflorum, with
its own pollen is described in "Forms of Flowers," Edition II., page 87:
his conclusions on the short-styled form (A) differ from those in the
present letter.)

September 28th [1861].

I am going to beg for help, and I will explain why I want it.

You offer Cypripedium; I should be very glad of a specimen, and of any
good-sized Vandeae, or indeed any orchids, for this reason: I never
thought of publishing separately, and therefore did not keep specimens
in spirits, and now I should be very glad of a few woodcuts to
illustrate my few remarks on exotic orchids. If you can send me any,
send them by post in a tin canister on middle of day of Saturday,
October 5th, for Sowerby will be here.

Secondly: Have you any white and yellow varieties of Verbascum which
you could give me, or propagate for me, or LEND me for a year? I have
resolved to try Gartner's wonderful and repeated statement, that pollen
of white and yellow varieties, whether used on the varieties or on
DISTINCT species, has different potency. I do not think any experiment
can be more important on the origin of species; for if he is correct we
certainly have what Huxley calls new physiological species arising. I
should require several species of Verbascum besides the white and yellow
varieties of the same species. It will be tiresome work, but if I can
anyhow get the plants, it shall be tried.

Thirdly: Can you give me seeds of any Rubiaceae of the sub-order
Cinchoneae, as Spermacoce, Diodia, Mitchella, Oldenlandia? Asa Gray says
they present two forms like Primula. I am sure that this subject is
well worth working out. I have just almost proved a very curious case
in Linum grandiflorum which presents two forms, A and B. Pollen of A is
perfectly fertile on stigma of A. But pollen of B is absolutely barren
on its own stigma; you might as well put so much flour on it. It
astounded me to see the stigmas of B purple with its own pollen; and
then put a few grains of similar-looking pollen of A on them, and the
germen immediately and always swelled; those not thus