INTRODUCTION 



The Laboratory Directions in General Physiology contained 

 herein have been used in the course at Princeton in a somewhat 

 modified form for the past two years. They have been printed as 

 an easy solution of the problem how best to prepare directions 

 for the student in laboratory courses. While not attempting 

 completeness in the field of General Physiology they will be found 

 to cover subjects of wider biological interest than those considered 

 in the Physiology Course of the Medical School. Many of the 

 experiments, particularly in nerve-muscle physiology, have been 

 taken from Cannon's "Laboratory Course in Physiology", Porter's 

 "Introduction to Physiology", and Stewart's "Exercises in General 

 Physiology" and I acknowledge my indebtedness to these sources. 

 I express also my deepest thanks to Dr. R. S. Lillie for many 

 suggestions anil for correcting the proof. A number of the experi- 

 ments performed in the General Physiology Course at the Univer- 

 sity of Pennsylvania under his direction are embodied in this book. 



E. N. H. 

 June i, 1913 



