320 Theory of Cell-formation [Book it. 



Mirbel at a late period in the iSth century; how Kurt 

 Sprengel, and with him a number of phytotomists, among 

 them Treviranus as late as 1830, supposed cells to be formed 

 from granules and vesicles in the cell-contents, an idea which 

 Link it is true opposed in 1807, but afterwards accepted to 

 a great extent. Though Moldenhawer as early as 181 2 

 (' Beitrage,' p. 70) distinctly rejected these theories, and pub- 

 lished observations which if followed up would have led to the 

 right path, yet the botanists above-named and others with them, 

 long continued to adhere to the earlier views. Kieser, for 

 example (' Memoire sur l'organisation des plantes,' 181 2) further 

 developed Treviranus' theory, that the fine granules in the 

 latex of plants are cell-germs which are afterwards hatched 

 in the intercellular spaces. Schultz-Schultzenstein in his work 

 ' Die Natur der lebenden Pflanze,' 1823-28, i, p. 607 rejected 

 this view and adopted that of Wolff and Mirbel. Scarcely 

 better than the notion of cell-germs represented by Sprengel, 

 Treviranus, and Kieser was the theory propounded by Karsten 

 soon after 1840; that of the French botanists Raspail and 

 Turpin 1 (1820-1830), though conveyed in a different termin- 

 ology, corresponded in its main points with the views of 

 Sprengel. 



It had been the good fortune of Mirbel at the beginning of 

 the century, and again thirty years later, to promote the 

 advance of phytotomy by means of important observations, 

 though he may have interpreted some of them incorrectly ; the 

 same thing happened again thirty years later, and it was a 

 German enquirer, von Mohl, who corrected his observations 

 and views on both occasions. 



In his famous treatise on Marchantia polymorpha, which 

 appeared in 1835 in the Memoirs of the French Institute, the 



1 On this point, see von Mohl's citation in * Flora ' of 1 82 7, p. 13. I have 

 not myself been able to consult the originals. 



