PREFACE 



PHYSIOLOGY, though dealing with the phenomena of living organisms, 

 has to use the same tools, whether material .or intellectual, as the 

 sciences of physics and chemistry. Any advances which are made 

 in these sciences not only increase our powers of attack upon physio- 

 logical problems but at the same time alter the intellectual standpoint 

 from which we view them. On the other hand, the investigation of the 

 phenomena of living beings is continually attracting our attention 

 and that of workers in the other branches of science to unexplored 

 regions in physics and chemistry. This mutual stimulation and co- 

 operation among the different sciences have as their result a continual 

 modification of our attitude with regard to the fundamental problems 

 of physiology. The present time has seemed to me, therefore, fitting 

 for the production of a textbook which, while not neglecting the data 

 of physiology, should lay special stress on the significance of these 

 data, and attempt to weave them into a fabric representing the prin- 

 ciples which are guiding physiologists and physicians of the present 

 day in their endeavours to extend the bounds of the known and to 

 increase their powers of control over the functions of living organisms. 



In a science such as physiology, based on so wide a discipline and 

 with so diverse a technique, it is almost impossible for any one man 

 to attain to a personal acquaintance with all its branches. In the 

 present book I have therefore not hesitated to avail myself of the 

 work of masters of the science in fields which I had not myself explored. 

 Thus, in the physiology of the nervous system, which has been trans- 

 formed and built up on a new basis by the researches of Sherrington, I 

 have endeavoured to follow this author as closely as possible. I am 

 also deeply sensible of my obligations to the writings of Tigerstedt, 

 Leathes, and Lusk on general metabolism, of Abderhalden and 

 Plimmer on physiological chemistry, of Bayliss on general physiology, 

 as well as to various authors of articles in the " Ergebnisse der 

 Physiologie," in Nagel's "Handbuch der Physiologic," and in Dr. 

 L. E. Hill's " Recent and Further Advances in Physiology." 



Although I have endeavoured to confine my demands on the 

 previous knowledge of the student within the narrowest possible 

 limits, I should recommend him in every case to read some primer 

 on physiology in order to obtain a bird's-eye view of the subject 



