SEEDS AND SOWING. 173 



Changes During Vegetation. 



Having at our disposal an excellent seed, planted in 

 a good soil and in the best manner, various adverse cir- 

 cumstances may yet arise — over which the farmer has 

 no control. As before stated, during the germinating 

 period a certain amount of humidity is necessary for the 

 development of the young plant, and, if this does not 

 exist, but negative results can be expected. During 

 the entire gi'owth of the root, the same principles exist, 

 but then the causes, and results produced are very 

 different from what they were during the first stage. 

 In using the manures it becomes evident that some 

 physical foi*ce must carry to the subsoil the chemical or 

 organic substance, and in this manner permit the root 

 to have at every period of its growth what it requires. 

 After the rain the air can enter more freely, etc., but as 

 much good as can be expected from a moderate amount 

 of rain, a eoi-responding harm will result when in ex- 

 cess, as the soluble portion of the fertilizer is likely to 

 be carried to a depth beyond the reach of the root, 

 and the latter would derive but little if any benefit 

 from the same. The argument also applies to the 

 temperature: a certain number of degrees are requisite 

 for the germination of the seed, and for the same reason 

 a certain number are necessary for the full growth of 

 the root. If this is in excess, secondary results will be 

 obtained. We consequently have two principles to 

 consider — the effects produced by the rain and the heat. 



