thers when kept in water in room;
but the paleae apparently do not open and expose stigma; but the stigma
could easily be artificially impregnated.

If I were you I would keep memoranda of points worth attending to.

2.X.II. MELASTOMACEAE, 1862-1881.

(620/1. The following series of letters (620-630) refers to the
Melastomaceae and certain other flowers of analogous form. In 1862
Darwin attempted to explain the existence of two very different sets of
stamens in these plants as a case of dimorphism, somewhat analogous to
the state of things in Primula. In this view he was probably wrong,
but this does not diminish the interest of the crossing experiments
described in the letters. The persistence of his interest in this part
of the subject is shown in the following passage from his Preface to the
English translation of H. Muller's "Befruchtung der Blumen"; the passage
is dated February, 1882, but was not published until the following year.

"There exist also some few plants the flowers of which include two sets
of stamens, differing in the shape of the anthers and in the colour of
the pollen; and at present no one knows whether this difference has
any functional significance, and this is a point which ought to be
determined."

It is not obvious why he spoke of the problem as if no light had been
thrown on it, since in 1881 Fritz Muller had privately (see Letter 629)
offered an explanation which Darwin was strongly inclined to accept.
(620/2. H. Muller published ("Nature," August 4th, 1881) a letter
from his brother Fritz giving the theory in question for Heeria. Todd
("American Naturalist," April 1882), described a similar state of things
in Solanum rostratum and in Cassia: and H.O. Forbes ("Nature," August
1882, page 386) has done the same for Melastoma. In Rhexia virginica Mr.
W.H. Leggett ("Bulletin Torrey Bot. Club, New York," VIII., 1881, page
102) describes the curious structure of the anther, which consists of
two inflated portions and a tubular part connecting the two. By pressing
with a blunt instrument on one of the ends, the pollen is forced out
in a jet through a fine pore in the other inflated end. Mr. Leggett has
seen bees treading on the anthers, but could not get near enough to
see the pollen expelled. In the same journal, Volume IX., page 11,
Mr. Bailey describes how in Heterocentron roseum, "upon pressing the
bellows-like anther with a blunt pencil, the pollen was ejected to
a full inch in distanc