of the most important figures in this advance of botany 

 from Schleiden's time was Naegeli, who brought to bear a 

 powerful intellect on many of the fundamental concepts 

 both of morphology and physiology. Of the many ques- 

 tions dealt with by him, that of the ultimate structure of 

 organized substance was perhaps the most far-reaching; 

 and today, despite its limitations, his Micellar Hypothe- 

 sis, is the most stimulating of any of the theories which 

 have been developed regarding this subject. 



The other milestone of progress was Darwin's "Origin 

 of Species" already referred to. Entirely aside from the 

 particular question involved in that work, its importance 

 lies in the fact that it fought the battle and won the victory 

 for the inductive method of reasoning as applied to bi- 

 ological science. Previous to the awakening of botany, 

 due to these and related causes, a botanist usually covered 

 the whole field of his science and had the right to consider 

 himself a specialist in all branches of botany. The rapid 

 accumulation of facts soon demanded, however, a segre- 

 gation of different lines of work. Thus arose the divisions 

 of botanical activity, which, for our purposes, may be 

 classed under three heads. First, the taxonomic, or as 

 more commonly called the systematic side, which has to do 

 with the classification, mainly as established by gross 

 morphology. Second, the morphological field which con- 

 cerns itself with the outward and inward form and struc- 

 ture and the development thereof, which may or may not 

 have direct relation with taxonomic work. Third, there 

 is the domain of physiology which treats of function. As 

 Professor Wilson has pointed out, there are really but two 

 divisions of biological work, the morphological and the 

 physiological, so that the separation of taxonomy which 

 really belongs in the first division is rather artificial. The 

 separation however is necessary for many reasons, among 

 which are the fact that the temper of mind and the 



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