from other plants.

Linnaeus took up the subject in the inauguration of his sexual system.
He first published his views in 1736, and he thus writes--"Antheras et
stigmata constituere sexum plantarum, a palmicolis, Millingtono, Grewio,
Rayo, Camerario, Godofredo, Morlando, Vaillantio, Blairio, Jussievio,
Bradleyo, Royeno, Logano, &c., detectum, descriptum, et pro infallibili
assumptum; nec ullum, apertis oculis considerantem cujuscunque plantae
flores, latere potest." He divided plants into sexual and asexual, the
former being Phanerogamous or flowering, and the latter Cryptogamous or
flowerless. In the latter division of plants he could not detect stamens
and pistils, and he did not investigate the mode in which their germs
were produced. He was no physiologist, and did not promulgate any views
as to the embryogenic process. His followers were chiefly engaged in the
arrangement and classification of plants, and while descriptive botany
made great advances the physiological department of the science was
neglected. His views were not, however, adopted at once by all, for we
find Charles Alston stating arguments against them in his _Dissertation
on the Sexes of Plants_. Alston's observations were founded on what
occurred in certain unisexual plants, such as Mercurialis, Spinach,
Hemp, Hop and Bryony. The conclusion at which he arrives is that the
pollen is not in all flowering plants necessary for impregnation, for
fertile seeds can be produced without its influence. He supports
parthenogenesis in some plants. Soon after the promulgation of
Linnaeus's method of classification, the attention of botanists was
directed to the study of Cryptogamic plants, and the valuable work of
Johann Hedwig (1730-1799) on the reproductive organs of mosses made its
appearance in 1782. He was one of the first to point out the existence
of certain cellular bodies in these plants which appeared to perform the
functions of reproductive organs, and to them the names of antheridia
and pistillidia were given. This opened up a new field of research, and
led the way in the study of Cryptogamic reproduction, which has since
been much advanced by the labours of numerous botanical inquiries. The
interesting observations of Morland, already quoted, seem to have been
neglected, and no one attempted to follow in the path which he had
pointed out. Botanists were for a long time content to know that the
scattering of the pollen from the anther, and its applic