CHAPTER III 



THE FUNCTIONS OF THE PARTS 



1. A plant then consists of definite parts of different 

 and distinct kinds. They are the organs of the plant, 

 and, like the organs of our body, have each their 

 own special work or function to perform, though one: 

 organ may do more than one kind of work, or the same 

 work may be done by more than one kind of organ. 



The study of these functions belongs properly to 

 Physiology, a branch of Botany into which we cannot 

 properly go till we have learnt something about the 

 inner structure of plants, but the more important 

 functions are not difficult to make out. As, however,, 

 all ordinary plants grow in the ground, we must first 

 find out the nature of soil. 



2. When a pit or well is being dug, the surface 

 soil is usually seen to be a very shallow layer from 

 a couple of inches to a foot in depth. Below it the 

 subsoil is nearly always lighter in colour and con- 

 tains pebbles and stones, which are larger at 

 lower levels, till it merges into solid rock. To find 

 out what soil consists of, put a small quantity in a 

 glass of water, and having stirred it well, leave it a. 



