14 



Effective Farming 



don) are .plainly marked. The stored-up food is called the 

 endosperm. 



Conditions necessary for germination. Moisture, warmth, 

 and oxygen are necessary for the germination of seeds. Live 

 seeds will not germinate if kept dry ; they must absorb a cer- 

 tain quantity of water before the seed-coat will burst and the 

 plumule and caulicle emerge. The seeds of different species 

 of plants vary as to the temperature at which they will sprout ; 



FIG. 2. Cross-section of a germinating maiz^ kernel. A, endosperm; 

 Cot, cotyledon ; Can, caulicle, or radicle ; PI, plumule. 



some seeds, like those of the sweet pea, will sprout at a rela- 

 tively low temperature, while others, cotton for example, re- 

 quire a higher temperature. Seeds will not sprout in a medium 

 that does not contain oxygen. In soil of good tilth air, and 

 therefore oxygen, is present in the spaces between the soil 

 particles. In a soil saturated with water, the air has been 

 crowded out and seeds planted in such soil will not germinate, 

 because of the lack of oxygen. 



Storing of seeds. Seeds should be stored in a cool dry place 

 where they can be protected from rats, mice, and other pests. 

 Both warmth and moisture are to be avoided in a storage house. 

 Warm, moist seeds that are subjected soon after to freezing 



