394 History of the Sexual Theory. [book hi. 



in Leipsic. In the course of the nine-days' journey the greater 

 part of the pollen escaped from the anthers, and Gleditsch 

 feared that it was spoilt ; but he was reassured by the Leipsic 

 botanist Ludwig, who had had experience in Algiers and Tunis, 

 and who informed him that the Africans usually employ dry 

 pollen that has been kept for some time for the purpose of fertili- 

 sation. Though the flowering of the female tree was nearly over, 

 he strewed the loose pollen on its flowers, and tied the withered 

 inflorescence of the male plant to a late-blowing shoot of the 

 female. The result was that fruit ripened in the following 

 winter, and germinated in the spring of 1750. A second 

 attempt conducted in a similar manner produced an equally 

 favourable result 1 . 



Koelreuter, who repeats this account in his ' Historie der 

 Versuche,' a record of the experiments made between the 

 years 1691 and 1752 on the sexes of plants, ends his nar- 

 rative with these words : ' These are, as far as I know, all the 

 attempts which have been made and described since the year 

 169 1 to prove the existence of sexes in plants.' Koelreuter's 

 book was written to show that experiment only can determine 

 the question of sexuality in the vegetable kingdom, and that 

 no one beside Camerarius, Bradley, Logan, Miller, and Gle- 

 ditsch had pursued this method up to 1752. 



While these botanists occupied themselves with the ques- 

 tion whether there was a distinction of sexes in the vegetable 

 kingdom, we meet with two writers at the beginning of the 

 1 8th century who regard sexuality as proved, and who take up 

 the question of the mode in which the pollen brings about the 

 formation of the embryo. Both were adherents of the theory of 

 evolution, bad observers, and not familiar with the literature 

 of the subject. The first is Samuel Morland. In the 



1 Koelreuter says that he sent pollen of Chamaerops in 1766 to St. 

 Petersburg and to Berlin, where it was successfully employed by Eckleben 

 and Gleditsch. He wished to try how long the pollen retains its efficacy. 



