SOURCES AND UTILIZATION OF PHYSIOLOGICAL MATERIAL 17 



both analytical and synthetical, but also the principles and methods of phys- 

 ics. Indeed, since the work of Helmholz, the interpretation of physio- 

 logical phenomena by means of physical laws and methods has contributed 

 more than any other means toward the prominent scientific position of 

 physiology at the present time. In a word, physiology must utilize the 

 facts of anatomy, histology, biology, physics, and chemistry to interpret the 

 phenomena of life. 



