HISTORICAL SKETCH 



and development of the ovule. He confirmed Amici's statement 

 that the pollen tubes make their way from the stigma to the ovule, 

 entering the latter through the micropyle. His lively imagination 

 carried him too far, however, for he asserted that the extremity of the 

 pollen tube pushes the membrane of the embryo sac before it and 

 directly becomes the embryonal vesicle, which then undergoes a 

 number of divisions to produce the embryo. The cotyledons were 

 said to arise laterally, while the 

 original apical point remained pr" r 

 more or less free and formed 

 the plumule. To him the em- 

 bryo sac was, therefore, a sort 

 of nidus or incubator within 

 which the end of the pollen tube 

 was nourished to give rise to 

 the new plantlet. If this were 

 really the case, there would of 

 course be no sexuality in plants. 

 Nevertheless, with the influence 

 he commanded and the sharp 

 tongue with which he denounced 

 all opponents, Schleiden found 

 a number of warm supporters. 

 One of them, Schacht, sponsored 

 this absurd idea with special en- 

 thusiasm. 



Amici boldly opposed the 

 views of Schleiden. In a meet- 

 ing of the Italian naturalists, 



held at Padua in 1842, he tried to prove that the embryo did not 

 arise from the tip of the pollen tube but from a portion of the ovule 

 which was already in existence and was fertilized by the fluid in 

 the tube. 



Schleiden (1845) gave a most spirited reply to this and said that 

 after his careful and thorough investigation of 1837 it was ridiculous 

 on the part of novices in the field to raise such meaningless objec- 

 tions. He described some fresh observations on Cucurbita and of- 

 fered to demonstrate the utter falsity of Amici's observations and 

 the complete truth of his own to anyone who visited him. 



Fig. 2. Matthias Jakob Schleiden. 

 (Photograph obtained through the cour- 

 tesy of Prof. W. Troll.) 



