LABORATORY MANUAL 

 OF GENERAL PHYSIOLOGY 



PREFACE 



The following experiments represent a year's laboratory work in the 

 elementary general physiology of animals. The subjects treated and the 

 sequence are obviously matters for each instructor to decide. Elaborate 

 quantitative experiments, so essential for a thorough understanding of 

 general physiology, are not included as these depend largely on the 

 equipment available in particular laboratories. Animal behavior is 

 treated first, owing to the availability of living material in October; and 

 the experiments serve to direct attention to the living organism. This 

 is important inasmuch as the next five topics are largely "test tube" 

 experiments. When students are thoroughly prepared in physical 

 chemistry this preliminary work on physical and chemical principles can 

 be considerably abbreviated. The next five topics deal largely with 

 irritability or the response of the organism to the external environment. 

 Topic XI, dealing with the permeability of living cells, might be studied 

 earlier in the course. Experience suggests, however, that it is desirable 

 to return to a consideration of first principles after an interval of gross 

 descriptive physiology, and the permeability experiments afford a lucid 

 interval which breaks the monotony of the kymographic routine in con- 

 nection with the study of muscular contraction and cardiac rhythm. 

 The last five topics (XII-XVI) deal with events occurring inside the 

 organism, i.e., the "milieu interieur" in the sense of Claude Bernard. 

 Topic XII, Temperature Characteristics, affords an appropriate transition 

 between the study of external and internal factors. Through the quanti- 

 tative analysis of the effects of an environmental factor (temperature), 

 some insight into the internal regulation of function is obtained. The 

 experiments on respiration are reserved for the end of the course when the 

 collecting season re-opens. It is not intended that all of the experiments 

 in each topic be performed (i.e., in VI, IX, XI and XIII the essential 

 principles involved can be illustrated by a judicious selection of experi- 

 ments). Owing to the general interest in vertebrates the experiments 

 involving invertebrate material are placed at the end of each section. 

 Illustrations are reduced to a minimum since diagrams cannot replace 

 actual demonstrations of apparatus. References to the literature are 



1 



