62 WILSON & TOOMKR FERTILIZER COMPANY 



cells. These cells are of different sizes and shapes accord- 

 ing to the work they have to do. They consist of the 

 cell wall, in which is the protoplasm, a semi-liquid jelly- 

 like substance surrounded by a thin, strong elastic mem- 

 brane. This protoplasm is the living substance of the 

 plant. In it the chemical changes take place the break- 

 ing down of different compounds ; the formation of vari- 

 ous vegetable substances, starch, sugar, etc. ; and the 

 use of these substances to the plant's best advantage. 

 The work within the plant is very intricate and is not 

 thoroughly understood by anyone, but it will serve our 

 purpose to consider that the soil water enters the roots, 

 rises to the leaves where it is elaborated (digested), and 

 returns by way of the inner bark to the different parts of 

 the plant where it is needed. 



