MODERN BIOLOGY 553 



Ndgeli' s cytological investigations 

 Nageli was certainly greatest as a cytologist; his studies of the dividing 

 of the pollen-grains and of the unicellular Algas have already been men- 

 tioned as epoch-making in their sphere, and through them he became one 

 of the pioneers of modern cytology. We may also include in this category 

 his studies of the sexual reproduction of the cryptogams, a problem that has 

 largely been elucidated by him. Nevertheless, his cell research had its weak- 

 nesses; the fact that he long maintains the old belief in independent cell- 

 formation is of less importance in this respect than the influence which he 

 permitted his theoretical speculations to exercise on the observations that 

 had already been made. In the field of vegetable anatomy a series of essays 

 that he wrote on the growth of the stem and root forms the basis of our 

 present-day knowledge of the subject. As a systematist he was especially 

 occupied in studying genera that possess abundant forms, but are difficult 

 to elucidate, chiefly Hieracium, the numerous and mutually overlapping mi- 

 crospecies of which he sought to explain by means of both natural observa- 

 tions and horticultural experiments. His experiences in studying this difficult 

 genus led him to speculate upon the term "species,"^ which formed the 

 basis of his evolutional theories. As a plant-physiologist he distinguished 

 himself chiefly in his investigations into the growth of starch granules, 

 whereby he laid the foundation of our knowledge of that curiously organized 

 structure in these elements of stored nutrition, which, as far as their chemi- 

 cal composition is concerned, are comparatively simple. Even in this line 

 of research, however, he became involved in theoretical speculations of that 

 abstract kind which had interested him since his youth. 



In a treatise Uber die Aufgabe der Naturgeschichte, dated 1844, Nageli has 

 given an account of the theoretical standpoint from which he started. He 

 lays down as the aims of natural research, firstly the discovery of fresh facts, 

 and secondly the creation of new laws of thought. His interest in these 

 latter are clearly reminiscent of his studies in the Hegelian school, referred 

 to above. True, he indignantly repudiates the accusations of Hegelianism 

 that were directed against him, but the likeness is nevertheless unmistakable 

 and gives his speculations a character all its own, which is strongly diver- 

 gent from, for instance, Haeckel's; while the latter speculates upon forms of 

 symmetry, the psychic qualities of matter, and other ideas reminiscent of 

 Schelling, Nageli is ever seeking to create fixed categories of thought, pref- 

 erably with reference to mathematical deductions. Above all, he strives to 

 create "absolute ideas," in which the various phenomena are to be defined. 

 All life is movement, and so all biology must be evolution, and from the 



' In contrast to Lamarck, Darwin, and even Haeckel, Nageli speaks in every way depreciat- 

 ingly of Linnaeus and his work for the advancement of classification. As is well known, these 

 views, which have but little justification, have since recurred in many German botanists. 



