HISTORICAL REMARKS 13 



In 1881 the author published a paper entitled, "The Anatomy of 

 the Photosynthetic Tissue-system of Plants," in which he adopted the 

 Sch wen denerian attitude ; subsequently other pupils of Schwendener, 

 such as Westermaier, Ambronn, Volkens, Tschirch, Zimmermann, etc., 

 assisted in developing this new branch of vegetable anatomy. As 

 early as 1884 the author was able in the original edition of the 

 present work to attempt, for the first time, a connected account of 

 the results that had so far been obtained along this line of investigation, 

 and, by means of his physiological classification of tissue-systems, to 

 outline a scheme into which all the various detailed observations might 

 in due course be fitted. Since that time a host of investigators have 

 been engaged in contributing to the advancement of physiological 

 anatomy. 



