CRYPTOGAMIC BOTANY 105 



some observations were made on Fungi and their mode of 

 development, but no comprehensive treatise dealing with 

 the lower forms of plant life came into existence till well 

 on in the nineteenth century, and any work actually 

 accomplished before that date was concerned chiefly 

 with the occurrence or non - occurrence of sexuality 

 among such organisms. 



After 1840 or thereabout sexuality in flowering plants 

 was universally accepted, since Amici's work in 1846 

 completed the story, for the earlier chapters of which 

 he and Robert Brown had been responsible. Schleiden 

 made an attempt in 1837 to show that the embryo was 

 formed from the apex of the pollen tube and that the 

 ovule acted merely as a nidus or nutrient bed for its 

 further development, but this absurd idea was soon 

 disproved by Amici, who, in 1842 and 1846, demonstrated 

 in the embryo-sac the presence of an ovum which was 

 fertilised by a " fluid " extruded from the tips of the 

 pollen tube. (Remember that the profound significance 

 of the nucleus was not at that time appreciated.) In 1856 

 Radlkofer finally gave Schleiden's hypothesis the " coup 

 de grace." 



In 1803 the Swiss theologian Vaucher noted conjuga- 

 tion in some of the lower green Algae, and suggested that 

 the fusion might be regarded as a sexual act, while 

 phenomena of a similar nature were also observed in the 

 lower Fungi. Several writers also recorded the occurrence 

 of sperms in Chara, Liverworts, and Mosses. Hedwig, 

 who was the first to study this last group at all carefully, 

 expressed the opinion that the antheridia and archegonia 

 in these plants corresponded to the stamens and carpels 

 of the Phanerogams. Similar organs were discovered 

 by Suminski, in 1848, on the prothalli (then spoken of as 

 cotyledons) of ferns, while some pioneer work was accom- 

 plished on Fucus by Thuret in 1845, and on Rhodophyceae 

 by Naegeli in 1846. Looking at the subject broadly, 

 however, it may be said that it was not until well after 



