vi ANIMAL PHYSIOLOGY. 
as this method implies would not be tolerated in the subject 
of morphology. ; 
While in the present work what is strictly applicable to 
other animals and to man has not always been kept apart, 
an effort has been made throughout to be cautious in all the 
conclusions drawn—a state of mind warranted by the past 
history and the present tendencies of physiology. Until our 
laboratory methods become more perfected, the comparative 
method more extensively applied, and conclusions drawn from 
“experiments” modified by comparison with the results of 
clinical, pathological, and all other available sources of infor- 
mation, I feel convinced that we are called upon to teach 
cautiously and modestly. 
Treating, as we do in our books, each subject in a separate 
chapter, there is, as I know by observation, the greatest danger 
that the student may get the idea that each function of the 
body is discharged very much independently; accordingly, 
there has been throughout a most persistent effort made to 
impress the necessity for ever remembering the absolute de- 
pendence of all parts. Unless this be thoroughly infused 
into a student, it is impossible that he can ever understand 
the wide world of natural objects, or the narrower one of un- 
natural (in a sense) organisms, as seen in the hospital ward. 
Recognizing how important it is to teach the young stu- 
dent to become an observer and an investigator in spirit and 
in some degree in fact, only such treatment of elaborate 
methods has been introduced as will enable him to form a 
general acquaintance with the modes in which laboratory 
work is carried on, while simple ways of verifying the essen- 
tial truths of physiology have been constantly brought before 
him. As to how far these are actually carried out will de- 
pend not a little on the teacher. The student who learns thus 
to observe and to verify will not fail to apply the method in 
his future career, whatever that may be—whether medical or 
other—nor is he so likely to throw his physiology overboard 
as a useless cargo as soon as his primary examination has 
been passed. 
