432 RELATION OF PLANT PHYSIOLOGY TO OTHER SCIENCES. 



inductive research period when these natural philosophical specula- 

 tions sought to establish themselves. Once again it was the return 

 to the inductive method and to the principle of the division of labor 

 which cleared the way to real progress. There came about a sharp 

 sundering of morphology from the doctrine of function — so sharp that 

 it was regarded as dangerous and punishable for one of these subjects 

 to deal with things pertaining to the other. Under the chastisement 

 of Schleiden no one attempted to demonstrate the functional signifi- 

 cance of a morphological structure. Narrow minded as this method of 

 procedure appeared, it was to the purpose. Embryology of plant organs 

 arose out of these conditions, and physiology was gathering richly of 

 usable constructive material for the future. 



Only a small part of morphology, which we botanists call anatomy, 

 but which is identical with the histology of the zoologists, developed 

 along with physiology. The greater part of morphology, which cor- 

 responds to what zoologists call anatomy, pursued its way independently 

 of physiology. 



I venture to raise the question here as to why zoology and botany 

 have not chosen the same expression for analogous branches of their 

 science; why under the term "anatomy" botanists and zoologists des- 

 ignate different things. The cause of this lies again in the principle 

 of division of labor, which at first always leads to a sharp separation, 

 and only after advances in scientific work does it bring about union. 

 The development of botany proceeded independently of zoology, and 

 vice versa. 



Terminology, taken at the beginning, is not of such serious impor- 

 tance, but subsequently it would be in accord with the ''economy of 

 science" if in related subjects similar expressions were employed to 

 express similar concepts. That will come to be the case; and even 

 now in botany the expression "histology" begins to be used in the same 

 sense as in zoology. 



The collaboration of working material in the form of demonstrated 

 facts on the side of morphology, as well as in the realm of the doctrine 

 of function, has aided in bringing the two nearer together, and the solu- 

 tion of the questions as to the functional significance of morphological 

 structures is in full tide. The most successful has been the union of 

 morphological and physiological knowledge as regards plant tissues, 

 the study of which, as previously mentioned, was from the first often 

 entangled with the doctrine of function. In this way has arisen in 

 recent times the much cultivated branch of botany to which has been 

 given the name of physiological plant anatomy. 



Bo field of research stands so near plant physiology as does 

 animal physiology. Where run, above all, the boundaries of these 

 two territories, when, in the lower stages of plant and animal organ- 

 isms, it is no longer possible to distinguish with certainty between 

 plant and animal, and when investigations are ever revealing new 



