CHAPTER XVII 



EXPERIMENTAL BIOLOGY 



I. 



Experimental Morphology 



THE HISTORY OF BIOLOGY might really close with the establishing of 

 the dissolution of Darwinism. This theory undeniably constitutes 

 a construction of thought of its own, and the ideas and methods 

 of research that have succeeded it are still in the developing stage, and their 

 possibilities of development can at best be only guessed at. A summary 

 glance at these conquests of the newest biology is nevertheless defensible 

 as a further justification for the defeat of the old ideas and in view of the 

 intrinsic interest that the new discoveries possess. The author, who himself 

 laboured exclusively in the sphere of the old morphology and who accord- 

 ingly does not feel justified in competing with the many splendid presen- 

 tations of the development of experimental biology that already exist, 

 proposes to make only very brief reference to the results of modern research 

 and give a short account of the theoretical reflections to which they have 

 given and may give rise. 



In a lecture given in 1900 in celebration of the birth of the twentieth 

 century, Oscar Hertwig gave a summary of the history of biology during 

 the past century. In it he sharply criticized physiology, which, in his view, 

 had created a brilliant experimental technique and had discovered a number 

 of facts concerning the chemical and physical processes of the organisms, 

 but, on the other hand, had neglected all other vital phenomena, with the 

 result that a whole category of the most important physiological problems 

 — namely, fertilization and embryonic development — had fallen entirely 

 into the hands of the morphologists and been dealt with by anatomists, 

 zoologists, and botanists. While the professional physiologists had thus re- 

 verted to "an empty mechanism" and imagined that the explanation of life 

 was only a chemico-physical problem, the morphologists discovered the 

 structural conditions in the fundamental elements of the body that are char- 

 acteristic of the phenomena of life and thereby extended the knowledge of 

 life in a sphere in which the methods of chemistry and physics have no part. 

 This accusation against the old classical physiology has certainly been to 

 some extent justified and is indeed confirmed by a statement made by one of 



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