CHAPTER I 



INTRODUCTION 



* 



THE world in which we live comprises two sepa- 

 rate and distinct classes of things the animate and 

 the inanimate, the living and the not-living. By 

 animate things we mean those which like animals 

 and plants feed, grow and reproduce each his own 

 kind. The not-living include rocks and stones, soil, 

 water and air. These may, indeed, be changed one into 

 another, for by the sun's heat and rain, the solid rock 

 of which this earth is composed is broken up into the 

 smaller pieces we call stones, and these again are still 

 further broken up and changed by rain and air into 

 soil. Water when warmed by the heat of the sun or 

 of a fire may be converted into an invisible vapour, 

 which passes away and mixes with the atmosphere, 

 and when cooled condenses and falls down again as 

 rain. But though these transformations are readily 

 brought about, no one would say that these substances 

 feed and grow and reproduce their kind in the same 

 sense that animals and plants do. 



Living things are divided into two great groups or 

 kingdoms the animal and the vegetable which, as far 



