160 HISTORY OF BOTANY 



where they find prepared for them a pollen-chamber or 

 cavity filled with fluid into which they shed their sperms. 

 In the higher Gymnosperms and in the Angiosperms the 

 zoidogamic method of fertilisation is abandoned, and in 

 the latter group the megasporangia, or ovules, become 

 further enclosed in the sporophylla, and fertilisation is 

 effected by the generative nuclei, conveyed to their 

 destination by a tube formed by the microspore, which, 

 after the pollen grain has been caught by the stigma, or 

 apex of the sporophyll, has to penetrate the style in order 

 to reach the" ovum. The whole problem for the Angio- 

 sperm, so far as reproduction is concerned, thus centres 

 round the transport of the pollen grain or microspore 

 from the stamen to the stigma, and the consequent 

 adaptation of the sterile floral leaves to facilitate this 

 transference a subject that was studied by many 

 workers from the days Conrad Sprengel, through Darwin 

 and Herman Miiller, down to a period, only a few years 

 ago, when Knuth gathered all the data together in his 

 great Handbook of Flower Pollination, of which an English 

 translation appeared in 1906 and following years. 



These are some, but only some, of the first-fruits 

 of the publication of Hofmeister's V ergleichende Unter- 

 suchungen and of Darwin's Origin of Species, and I think 

 you will now agree with me in regarding the year 1859 

 as a date of as great interest and importance in the 

 history of botany as 1066 is in the history of Britain. 



