378 KARL WILHELM YON NALGELI. 



time when botanists were comparatively few and accurate observa- 

 tions scant;^, should, in the light of accumulated modern observa- 

 tions, be superseded by other more tenable theories ; but we must 

 still continue to acknowledge that we are indebted to Naegeli for 

 the solid foundation of more than one of the branches of botany 

 which are now regarded as among the most interesting and imjjortant 

 fields of modern research. 



Naegeli was neither a pure sj'^stematist, nor strictly a physi- 

 ologist in the modern sense. If he pursued systematic studies 

 to some extent, it was with the view of preparing himself to dis- 

 cuss the abstract questions of the nature of species and the theory 

 of descent. His detailed work on the genera Cirslum and Hiera- 

 c'lum was undertaken with very much the same purpose as that of 

 Darwin in his work on Cirrhipeds; namely, by mastering the 

 specific differences to be found in a few large and variable genera, 

 to prepare himself for the intelligent discussion of the relations 

 and probable origin of species in general. Beyond this he felt 

 little interest in systematic work. So far as his work on the na- 

 ture of cell structure, the formation of the cell wall, the method of 

 reproduction in Cryptogams, and the phenomena of fermentation 

 is concerned, it was certainly physiological rather than systematic; 

 but, using the terminology of the present day, it may be said that 

 Naegeli was pre-eminently an histologist, and that the greater part 

 of his theories and general views, so far as they were derived from 

 his own work, had a histological basis. Unlike De Bary, Prings- 

 heim, and the younger generation of German botanists, he did not 

 attempt, to any extent, to study what may be called the life-history 

 of any special group by means of cultures. 



The histological work of Naegeli was admirable, and he was 

 practically the first to introduce histological methods into the study 

 of algte and other groups. In his ''Die neueren Algensysteme 

 und Versuch zur Begriindung eines eigenen Systems der Algen und 

 Florideen " (1847) he accumulated a large mass of facts, and was 

 the first to give an accurate account of the thallus of different 

 species, and to show the necessity for studying tlie apical growth 

 as a means of classification in this group. In his attempt to form 

 a new system of classification he was less successful. He excluded 

 the Floridece from algae; but although he was accurate as far as 

 concerned the microscopic structure which lie studied, he failed to 

 recognize the true sexual relations of the FIoridecB. In his i)aper 

 " P)eitr{ige zur Morphologic und Systomatik der Ccramiacoa; " 



