Journal of Proceedings.
cxxvii
exhibited by Mr. Smith and his friends, was a wonderful object. As far
as he knew, no one, with the exception of Mr. Spurrell and himself, had
heretofore been able to replace Palaeolithic flakes.
Remarks on the paper were also made by the President and by Mr.
Meldola, and the vote of thanks to Mr. W, H. Smith and his coadjutor's
was very heartily passed.
In the absence of the authors, the following paper was read by
Professor Boulger, who illustrated many of the statements by drawings
on the black-board :—
On the Transmission of "Form" in Heterostyled Plants.
By Edwd. Rosling, F.R.M.S., and Miller Christy.
In his exceedingly interesting work, 'The Different Forms of Flowers
on Plants of the same Species.' Mr. Darwin, after treating fully of " The
means by which plants may have been rendered heterostyled," says
(p. 268): "the transmission of the two forms by heterostyled plants
. . . . may perhaps be found hereafter to throw some light on their
manner of development." The point is one, however, to which Mr.
Darwin seems to have given very little attention, for his remarks upon it
occupy scarcely more than four pages of his work (pp. 268 to 272
inclusive). It therefore appeared to us desirable that some further
information upon the matter should be obtained, and Mr Rosling accord-
ingly undertook to conduct some experiments, as announced in Mr.
Christy's paper on the Essex members of the genus Primula (Trans.
Essex Field Club, vol. iii., p. 156). We here give the results of these
experiments.
It will, of course, appear probable to every one that, as heterostyled
plants require a reciprocal union to ensure full fertility, the offspring of
such a " legitimate "union will consist of plants belonging to both forms.
This is rendered a still more reasonable conclusion, as Mr. Darwin has
been able to show that the offspring of an illegitimate union is, almost
without exception, of the same form as the parents ; while Hildebrand,
Fritz Muller, and Darwin all found that " a very large proportion,
or all, of the offspring from a legitimate union between any two forms of
the trimorphic species of Oxalis, belonged to the same two forms." We
are not aware, however, of any published observations actually showing
whether this is so or not, or to what extent—i.e., whether, in nature, the
different forms of heterostyled plants transmit to their offspring their
own form only (i.e., the form of the seed-parent), or their own most
strongly, or both forms indifferently.
We are perfectly aware that the results of our experiments are very
meagre and somewhat unsatisfactory, having been made on two occasions
only, upon no more than three species, all of which were dimorphic and
belonged to a single genus—the genus Primula ; but we trust that, at
any rate, they will assist in solving the problem. Obviously, if abso-
lutely reliable results are to be obtained, many experiments must be
made at different times on as many species as possible ; but this would
be difficult of accomplishment.
Before proceeding further, it may not be amiss to summarise briefly
the rather meagre remarks on this subject made by Mr. Darwin. He
gives two tables (36 and 87, pp. 269 and 270) which, he says, contain
"all the known cases." The first shows the nature of the offspring
obtained on ten different occasions from illegitimate unions of six
species of dimorphic plants ; the second gives the result of eight experi-
ments on three different species of similarly fertilised trimorphic plants.