PROGRESS IN CRYPTOGAMIC BOTANY 171 



by Russow and De Bary, and special points received 

 attention from Janczewski, Treub, Haberlandt, Dangeard, 

 and Le Clerc du Sablon. If the personal reference be 

 pardoned, the comparative anatomy of a large number 

 of species was investigated by myself between 1893 

 and 1902. 



A mere catalogue of names such as I have just given 

 you can have but little meaning unless you take the 

 trouble to study the individual monographs for yourselves, 

 or at least the summaries of their contents from such 

 references and quotations as you will find in Campbell's 

 Mosses and Ferns or in Bower's Origin of a Land Flora, 

 the best book I know of on the subject, and which I 

 earnestly recommend you to study with the utmost care. 

 If I were to omit all notice of the authors whose names 

 I have quoted you might think I regarded them as of 

 little importance, or blame me for overlooking them 

 altogether when you encountered their names in other 

 works. To mention them without discussing the results 

 they achieved is, I frankly admit, a compromise, but one 

 demanded by the exigencies of time and space. 



The Mosses and Liverworts did not attract nearly so 

 much attention during the period of which I am speaking. 

 The outstanding name is undoubtedly that of Leitgeb, 

 who published several important researches on the 

 Hepaticae between 1868 and 1886. To Farmer we owe 

 also much of our knowledge of the cytology of the groups, 

 especially the discovery of centrospheres associated with 

 the nucleus during division, a subject that had attracted 

 the attention of the zoologists in relation to cell division 

 in the animal kingdom. Pringsheim and Stahl also 

 studied the protonemata of the Musci and the mode of 

 origin of the gametophores from them, while Kienitz- 

 Gerloff elucidated the structure of the sporogonium. 



Very considerable progress was also made in our 

 knowledge of Algae, both systematically and anatomically. 

 Thus, in addition to the Species, Genera et Or dines Algarum 



