10 



given in this book; some are in the text 

 proper, but more appear in the Glossary. 

 Most of our scientific terms came from 

 Greek (Gr.) and Latin (L.) words. 



SCOPE OF ZOOLOGY 



Fields of the zoological sciences 



Zoology (Gr. zoioir, animal; logos, dis- 

 course) is the science of animals, whereas 



COLLEGE ZOOLOGY 



botany is the science of plants. The com- 

 bined study of animals and plants forms the 

 science known as biology. The facts about 

 animals alone and the methods of studying 

 them have become so numerous that one 

 man in his lifetime can master and become 

 an authority on only one, or at most, a few 

 phases of the subject. It has, therefore, been 

 found necessary and convenient to divide 

 zoology into a number of sciences. Some of 

 the principal subdivisions of zoology are in- 

 dicated in Fig. 2). 



CYTOLOGY 



Structure and 

 functions with- 

 in cells 



ANATOMY 

 Structure of the 

 animal body 



PATHOLOGY 



Nature of diseases, 

 causes and symptoms 



PHYSIOLOGY 



Functions of organisms 



ECOLOGY 



Relations of organisms 

 to their environment 



PALEONTOLOGY 

 Fossil organisms 



SOCIOLOGY 



Animal societies 

 including man 



HISTOLOGY 



Microscopic structure 

 of tissues and organs 



TAXONOMY 

 Classification of 

 organisms 



GENETICS 

 Heredity 



EMBRYOLOGY 

 Developmental stages 

 of organisms 



ZOOGEOGRAPHY 

 Geographical distribu- 

 tion of animals 



Figure 2. Some of the main subdivisions of zoology with concise definitions. 



Many other zoological fields are recog- 

 nized other than those in Fig. 2. These are 

 often devoted to a study of a group of ani- 

 mals of special interest or importance. For 

 example, parasitology is the study of para- 

 sitic organisms; protozoology, of Protozoa; 

 entomology, of insects; malacology, of mol- 

 lusks; ichthyology, of fish; herpetology, of 

 reptiles and amphibians; ornithology, of 

 birds; mammalogy, of mammals; medical 

 zoology of animals that affect the health of 

 man, etc. 



Certain zoological sciences are involved in 

 the study of each of the animal types de- 

 scribed in this book. These include particu- 

 larly those dealing with gross structure 

 (anatomy), microscopic structure (histol- 

 ogy), cellular structure (cytology), develop- 

 ment of the individual (embryology), func- 

 tion (physiology), behavior (psychology), 

 classification (taxonomy), and origin (phy- 

 logeny). Certain zoological sciences of a 

 more general nature are considered in sepa- 

 rate chapters; these are nutrition, coordina- 



