CHAPTER III. 



EXAMINATION OF THE MATURED FRAMEWORK OF CELL- 

 MEMBRANE IN PLANTS. 



1800-1840. 



THERE is no sharp line of division between the i8th and the 

 i gth centuries; the phytotomists who appear on the scene 

 during the first years of the new century are scarcely more 

 successful than Hedwig and Wolff; careful and judicious 

 interpretation of their own and others' observations is still rare, 

 and they are often misled by preconceived opinions. 



In one respect indeed a very great improvement appeared 

 with the commencement of the igth century; the number 

 of phytotomists working contemporaneously, checking and 

 criticising one another, became all at once much larger. 

 Hitherto ten or twenty years had intervened between every 

 two works on phytotomy ; but in the course of the twelve 

 years after 1800 nearly as many publications followed one 

 "a'nother, and scientific discussion enlivened enquiry. Now 

 we meet with a Frenchman for the first time in the field 

 of phytotomy, Brisseau Mirbel, who brought out his 'Traite 

 d' Anatomic et de Physiologic Vegetale' in 1802, and raised 

 a series of questions in the discussion of which several German 

 botanists, Kurt Sprengel (1802), Bernhardi (1805), Treviranus 

 (1806), Link and Rudolphi (1807), at once took part. It was 

 a step in advance and one affecting all botanical studies, that 

 with the exception of Rudolphi all these men, like Hedwig 

 before them, were botanists by profession ; it was at last felt 



