EXTRACT FROM THE PREFACE TO 

 THE FIRST EDITION 



IN this book an attempt has been made to interweave formal ex- 

 position with practical work, according to a programme which I 

 have followed for some time past in teaching Physiology to medical 

 students on the other side of the Atlantic, and which has, it is 

 believed, proved to be well adapted to their needs and opportunities. 

 It ought, however, to be explained that, for various reasons, a 

 somewhat wider range of experiment is open to the student in 

 America than in this country. But as nobody will use this book 

 except in a regular laboratory and under responsible guidance, it 

 has not been thought necessary to mark in any special manner the 

 parts of the exercises which the English student must do by proxy 

 (that is, learn from demonstrations), and the parts he ought to 

 perform for himself. 



An arrangement of the exercises with reference to the systematic 

 course has this advantage that by a little care it is possible to 

 secure that practical work on a given subject shall actually be going 

 on at the time it is being expounded in the lectures. Cross-refer- 

 ence from lecture-room to laboratory, and from laboratory to 

 lecture-room, from the detailed discussion of the relations of a 

 phenomenon to the living fact itself, is thus rendered easy, natural, 

 and fruitful. 



As" some teachers may wish to know how a course such as that 

 described in the Practical Exercises may be conducted for a fairly 

 large class, a few words on the method we have followed may not 

 be out of place. It is obvious that many of the exercises require 

 more than one person for their performance; and it may be said 



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