FIRST PRINCIPLES OF AGRICULTURE 



1. DEAD AND LIVING MATTER. 



Illustrative material: A few grains of sand on a piece of 

 paper. Examine the grains carefully. 



Dead Matter. Figure i shows a grain of sand as it 

 appears under the microscope. Its corners have been 

 rounded by rubbing against other 

 grains of sand. It can not move; 

 it can not change its form. We 

 might leave it under the microscope 

 and look at it daily for a year, and it 

 would look just the same every time. 



FIG. i. Grain of sand, * * 



magnified ]_ never grows larger and never di- 



vides into other grains of sand unless it is broken by 

 some outside force. It has no life; it is dead. 



Living Matter. Figure 2 

 shows some yeast plants as 

 they appear under the micro- 

 scope. The yeast plant is so 

 small that it can be seen only 

 with a microscope. Each yeast 

 plant consists of a closed sack 

 or cell, containing a jellylike FlG- 2- _ Yeast plants> magnified 

 liquid called protoplasm, which 



is the living substance of the cell. Within the protoplasm 

 is a central body called the nucleus. If we watch the yeast 



9 



