434 History of the Sexual Theory. [BOOK in. 



approximation to the ideas of Morland and Geoffroy ; and if it 

 were correct, it would like these imply the necessity of pollina- 

 tion to the formation of seeds that should contain embryos, but 

 at the same time it would do away with that which is the essen- 

 tial point in the sexuality of plants, for the ovule would merely 

 be the spot adapted to the hatching of the embryo formed from 

 the pollen. Schleiden's idea was at once adopted by Wydler, 

 Gelesnow and various other botanists, and especially by 

 Schacht, but the most eminent microscopists withheld their 

 assent. Amici was the first who openly opposed the new doc- 

 trine ; before the Italian congress of savants at Padua in 1842 

 he endeavoured to prove that the embryo is not formed at the 

 end of the pollen-tube, but from a portion of the ovule which 

 was already in existence before fertilisation, and that this part 

 is fertilised by the fluid contained in the pollen-tube. But the 

 choice of a gourd, a plant eminently unsuitable for his pur- 

 pose, prevented his discovering the exact details of the process, 

 and Schleiden did not hesitate to denounce his assertions in 

 1845 in the plainest terms. But in the next year (1846) Amici 

 produced decisive proof for the views which he had maintained ; 

 he showed from the Orchidaceae, which were peculiarly well 

 adapted for such investigations, not only that Robert Brown's 

 doubts above mentioned were without foundation, but, which 

 is the main point, that a body, the egg-cell, is present in the 

 embryo-sac of the ovule before the arrival of the pollen-tube, 

 and that this body is excited by the presence of the pollen-tube 

 to further development, the formation of the embryo. He 

 gave a connected account on this occasion for the first time of 

 the whole course of these processes from the pollination of the 

 stigma to the perfecting of the embryo. 



The correctness of the account given by Amici was con- 

 firmed in the following year by von Mohl and Hofmeister, the 

 latter of whom described in detail the points which were 

 decisive of the question from a variety of plants, and illustrated 

 them by very beautiful figures in a more copious work, ' Die 





