GENERAL PHYSIOLOGY 83 



graphic records made by instruments of precision has 

 come to represent one especial phase of modern 

 physiology. 



The other marked line of physiological investiga- 

 tion has been in the domain of chemistry, where 

 Wohler, Liebig, Kiihne, and others have, through the 

 chemical changes occurring in its body, observed the 

 various activities that take place within the or- 

 ganism. Some of the more recent observations have 

 made a particular feature of the study of chemical 

 changes taking place within living matter. The 

 prodigious development of organic and biological 

 chemistry has shown the close interrelationship of 

 chemistry, physiology and biology. 



The physiological method has been much applied 

 in zoological study. Besides the important investiga- 

 tions carried on by zoologists under the title of 

 "Experimental Morphology" there has arisen a 

 recognized division designated experimental zoology 

 which is chiefly physiological. 



General physiology is so intimately related that all 

 students of zoology should take occasion to become 

 acquainted with Verworn's admirable treatise on 

 General Physiology. 



