PREFACE. 



It is admitted beyond all question that even an 

 elementary study of human physiology ought to be 

 preceded by a more or less thorough dissection of 

 some mammal. This little book, prepared originally 

 for the author's own class, is intended to give this 

 necessary anatomical basis to those who have not the 

 opportunity of dissecting the human body. With this 

 purpose in view, attention has been directed to those 

 organs which are the chief objects of physiological 

 study, rather than to those which have mainly an ana- 

 tomical interest. One chapter has been inserted 

 treating of the anatomy of the muscles of the shoulder 

 and arm, but the author does not think it advisable to 

 require this of a class unless there is abundance of 

 time at the teacher's disposal. The anatomy of these 

 muscles is of no particular importance in general phy- 

 siology, and even from the standpoint of comparative 

 anatomy it has but little value owing to the incom- 

 plete knowledge possessed with regard to muscle 

 homologies among the mammalia. With reference to 

 the muscles of the abdomen and the thorax the case 

 is very different : these muscles play an important part 

 in the performance of the respiratory movements, and 

 their position and relations ought to be known by the 

 student. Descriptions of these muscles, therefore, 



