INTRODUCTION' 19 



Zoology, a Biological Science 



The name, zoology, which is derived from the Greek words zoos, 

 animal, and logos, discourse on, refers to the study or science of 

 animals. The natural sciences, as distinguished from the social 

 sciences, are conveniently divided into two groups: the physical 

 sciences, such as chemistry, physics, and astronomy, which deal with 

 nonliving bodies; and the biological sciences, such as botany and 

 zoology, which are concerned with living organisms. Zoology and 

 botany together constitute the science of biology. The expression 

 animal biology is often used as a synonym for zoology. A person 

 who specializes in the study of zoology is known as a zoologist. There 

 was at one time an erroneous popular impression that zoologists were 

 simply '* bug-hunters." This conception of the field has been greatly 

 expanded until now it is considered one of the valuable and serious 

 fields of science. 



The Subdivisions of Zoology 



Zoology as one of the divisions of the general field of biological 

 science is such a broad field that it is necessary to subdivide it into 

 several subdivisions for convenience in study. It has been a rela- 

 tively short time since all of the know^n biology, geology, and re- 

 lated subjects were studied under the head of natural history. But 

 now the subject matter of zoology alone has grown to such mag- 

 nitude 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. It is one of the older fields, and is 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 dissection, observation, and study 

 of the parts, form, and relationship of parts of the digestive system 

 of the cat would be a good example of anatomical study. 



B. Histology or Microscopic Anatomy, is a study of the microscopic 

 structure of the various parts of the animal body. The histologist 

 studies the relationship and arrangement of the cells as they cooper- 

 ate to comprise the substance of the organism. 



