4 PLANT BIOLOGY 



animals has made possible the scientific treatment of disease, 

 and what is more important, the prevention of disease. As 

 our knowledge of the living and lifeless world has increased, 

 it has become necessary to divide this knowledge into a great 

 many different branches, some of which are physics, chemis- 

 try, geology (a study of the earth), mathematics, psychology 

 (a study of mind), and biology. 



7. Biology (from Greek, bi'os = life + lo'gos = discourse) is 

 the general name given to the study of all living things. 

 Hence, this science treats of both animals and plants. If we 

 confine our study to the structure and activities of plants 

 alone, we call this part of the science plant biology, or botany. 

 Animal biology, or zoology, on the other hand, treats of ani- 

 mals. So-called human physiology (better known as human 

 biology) discusses man, the highest type of the animal king- 

 dom ; hence, it is a branch of the science of zoology, which in 

 turn is one of the subdivisions of the study of biology. 



