lated, and towards 1845 it began to be possible by critical
examination of them to arrive at something like a clearer
understanding of this part of botany. The majority of
botanists readily accepted Schmidel's and Hedwig's opinion
with respect to the Mosses; Vaucher had as early as 1803
maintained that the long-known conjugation of Spirogyra was a
sexual act; Ehrenberg observed in 1820 the conjugation of a
Mould, Syzygites; Bischoff and Mirbel explained the organisation of the antheridia of the Liverworts in 1845, while Nees
von Esenbeck saw the spermatozoids of Sphagnum in 1822
and Bischoff those of Chara in 1828, though they were at first
taken for Infusoria, an opinion maintained by Unger as late as
1834. But it was Unger[1], who in 1837, after careful study of the spermatozoids of the Mosses in 1837, declared them to be
the male organs of fertilisation; in 1844 Nägeli discovered
corresponding forms on the prothallium of Ferns, which had
till then been called a cotyledon, and in 1846 the spermatozoids
of Pilularia, the products of the small spores which Schleiden
had explained to be the pollen-grains of that plant.
These facts were of the highest importance, but little was to be made of them as long as the female organ in the plants in question, the Mosses excepted, was unknown, and meanwhile it was only the resemblance between vegetable and animal spermatozoids which led to the conjecture, that the one had the same sexual significance as the other.
Light was suddenly thrown upon the subject, when Count Lesczyc-Suminsky discovered in 1848 on the supposed cotyledon (prothallium) of Ferns both the antheridia and the peculiar organs, inside which the embryo or young fern is formed. Though the statements respecting the structure and development of these female organs and of the embryo were inaccurate in some important points, yet the place was now indicated
- ↑ The authorities for these statements are collected by Hofmeister in 'Flora,' 1857, p. 120, etc.
