Morphology and Systematic Botanv. 183 



securing of the facts demands all the powers which specially 

 display the individual character of the observer. Thus serious 

 attention to microscopy was one of the causes which intro- 

 duced the best observers to the practice of inductive enquiry, 

 and gave them an insight into its nature ; and in a few years' 

 time when the actual results of these investigations began 

 to appear, and when a wholly new world disclosed itself to 

 botanists, especially in the Cryptogams, then questions arose 

 on which the dogmatic philosophy had not essayed its ancient 

 strength ; the facts and the questions were new and untouched, 

 and presented themselves to unprejudiced observation in a 

 purer form than those, which during the first three centuries 

 had been so mixed up with the old philosophy and with the 

 principles of scholasticism. Von Mohl, who only occasionally 

 occupied himself with morphological subjects, was a firm 

 adherent of the inductive method, and was bent on the 

 establishment of individual facts rather than of general 

 principles ; but the founders also of the new morphology, 

 Schleiden and Nageli, started from philosophical points of 

 view, which, different as they were in the two men, had yet 

 two things in common, a demand for severely inductive 

 in vestigation as the foundation of all science, and the rejection 

 of all Ideological modes of explaining phenomena, in which 

 latter point their opposition to the idealistic nature-philosophy 

 school was most distinctly manifested. They had indeed one 

 very important point of contact with this school, the belief in 

 the constancy of organic forms ; but this belief, not being 

 connected with the Platonic doctrine of ideas, was with them 

 only a recognition of evcry-day observations, and was therefore 

 of less fundamental importance, being felt merely as an 

 inconvenient element in the science. Treating the question 

 in this way, and influenced by the results of the new researches, 

 they either inclined to entertain the idea of descent before the 

 appearance of Darwin's great work, or gave a ready assent to 

 the principle of the new doctrine, though they expressed some 



