ZOOLOGY. 



INTRODUCTION. 



NATURAL HISTORY, strictly speaking, includes the study 

 of all natural objects, whether animate or inanimate. It 

 consists of two great divisions : -first, that which treats 

 of inorganig or dead bodies ; second, that which deals with 

 organic or living substances. The sciences which treat of 

 inorganic bodies are termed Mineralogy and Geology, 

 while that which deals with the properties common to 

 organic beings (plants and animals) is termed Biology 

 (Gr. bios, life; logos, a discourse). This science com- 

 prises Botany (Gr. botane, a plant), which treats of the 

 properties of plants, and Zoology (Gr. zoon, an animal; 

 logos, a discourse), which investigates the nature and 

 habits of animals. In the popular use of the term, 

 Natural History is often synonymous with Zoology. 



The most important differences between organic and 

 inorganic bodies are : 



1. Inorganic bodies are either indefinite in shape (amor- 

 plious), or assume regular forms called " crystals," which 

 are bounded by plane surfaces and straight lines. Organic 

 bodies are generally definite in shape, and are bounded by 

 curved lines and rounded surfaces. 



Inorganic bodies increase in size by the addition of 

 similar particles to the outside. Organic bodies grow 

 by the receiving and assimilation of matter into the 

 interior. 



