MOISTURE 



9 



long periods of time, but when placed in moist surroundings 

 they absorb water rapidly and in great abundance, swell and 

 sprout very quickly. 



Oxygen from the air is also of very great importance in the 

 sprouting of seeds. Even when seeds are supplied with the 

 proper warmth and the proper amount of water but deprived of 

 oxygen they will not grow. 



Fio. 4. a, Longitudinal section of corn seed showing the embryo; b and c, the germi- 

 nating seed showing the emergence of the root and plumule, the formation of rootlets and 

 root-hair. 



Moisture. However, it is possible for the seeds of some 

 plants to have too much water, which will affect the tempera- 

 ture and interfere with the plant securing the necessary oxygen. 

 In fact, the little embryo plant may be smothered or drowned 

 in very much the same manner as an animal may be killed 

 when submerged in water, but of course it requires more time. 

 Every farmer knows that land for certain crops must be well 

 drained and that too much rainfall in the spring interferes 

 with proper germination, causes grain to rot in the field, and 

 causes those plants that survive to be yellow and weak. 



