viii PREFACE. 



followed. The bodily structure most interesting to man, 

 his o^vn, was the first studied (directly or indii-ectly), and 

 the names now given to dift'erent parts of the bodies of the 

 lower animals have been mainly derived from human 

 anatomy. The descending course is also that which 

 seems, on the whole, preferable, for thus, by commencing 

 with the class of animals to which man belongs, we may 

 proceed from the more or less known to the unknown, and 

 from that which is comparatively familiar, to that which is 

 strange and novel. 



Having then chosen to begin the study of Animals and 

 Plants with that class to which we belong, it might 

 perhaps be expected that Man himseK would be chosen as 

 the type. But a fresh description of human anatomy is 

 not required, and would be comparatively useless to those 

 for whom this work is especially intended. For a satis- 

 factory study of animals (or of plants) can only be carried 

 on by their direct examination — the knowledge to bo 

 obtained from reading being supplemented by dissection. 

 This, however, as regards man, can only be practised in 

 medical schools. Moreover, the human body is so large 

 that its dissection is very laborious, and it is a task 

 generally at first unpleasing to those who have no special 

 reason for undertaking it. But this work is intended for 

 persons who arc interested in zoology, and especially in 

 the zoology of beasts, birds, reptiles, and fishes, and not 

 merely for those concerned in studies proper to the medical 

 profession. 



The problem then has been to select as a type for 

 examination and comparison, an animal easily obtained and 

 of convenient size ; one belonging to man's class and one 

 not so different from him in structure but that comparisons 

 between it and him (as to limbs and other larger portions 

 of its frame) may readily suggest themselves to the 



