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TEXTBOOK OF ZOOLOGY 



ral history. But now the subject matter of zoology alone has grown 

 to such magnitude that it has become necessary to divide it into 

 numerous special fields. These subdivisions may be summarized as 

 follows : 



1. Morphology is the study of the form and structure of the 

 bodies of animals. Its organization as a special field of study oc- 



Fig. 1. — Divisions of study in the field of biology. (Modified from several authors.) 



curred at about the beginning of the nineteenth century. It is now 

 further divided into several branches. 



A. Gross anatomy, which literally means cutting up, includes all 

 that may be studied of form and structure of bodies by dissecting 

 them. Human anatomy, which is one of the fundamental subjects of 

 study in the preparation of the medical student, is usually separated 

 from comparative anatomy. The latter study comprises a compara- 



