ELEMENTS OF BIOLOGY. 



CHAPTER I. 



DEFINITION OF BIOLOGY. 



All natural objects admit of an obvious separation into 

 two primary groups, according as they are dead or alive — 

 according as they exhibit no phenomena except such as 

 can readily be referred to the working of known physical 

 and chemical laws, or as they present, in addition, the phe- 

 nomena which we are accustomed to group together under 

 the name of " vital." The studies which occupy themselves 

 with, dead bodies concern the physicist, the chemist, the 

 geologist, and the mineralogist. The study of living be- 

 ings, irrespective of the exact nature and position of these, 

 is the province of Biology (Gr. bios, life ; logos, a discourse). 

 All living beings, however, may be divided into the two 

 kingdoms of animals and plants, the study of the former 

 constituting the department of Zoology, whilst Botany is 

 exclusively concerned with the latter. In accordance with 

 this division, Biology splits up into the kindred sciences of 

 Zoology and Botany, and properly includes both of these in 

 all their details. Here, however, nothing more is aimed at 

 than the presenting to the student, in a concise form some 



