SEED AND SEED SOWING. 69 



erence to earliness and productiveness, I would not ad- 

 vise the saving of these. 



Plants like the sugar cane, the sweet and Irish potato, 

 which have been propagated exclusively for years from 

 cuttings or tubers, cease bearing matured seed. The 

 potato does occasionally produce seed; but more fre- 

 quently at the North than at the South. Should seed of 

 Southern production be desired for the creation of new 

 varieties, it might be possible to induce some of the lafce, 

 not very productive, varieties to perfect seed by prevent- 

 ing the plants from bearing tubers, by their removal 

 while small. This will encourage the flow of nutritive 

 matter to other parts, just as contrary wise, the removal 

 of flowers will increase the size of tubers. 



CAUSES OF FAILURE. 



If, after a seed is consigned to the soil, the changes 

 which it undergoes during germination proceed without 

 interruption, the young plant will in due time make its 

 appearance in a healthy state; but when severe changes 

 in the state of the weather occur, it may perish. If all 

 seeds sprouted as promptly and with* as much vigor as 

 those of the radish, there would be little uncertainty at- 

 tending seed sowing; but many varieties, large and 

 small, remain in the ground from a few days to several 

 weeks, during which interval unpropitious changes of the 

 weather may occur; a fall of temperature sufficient to de- 

 stroy the barely sprouted seed below the surface may 

 supervene; or the weather may become so wet as to rot the 

 seed before germination has taken place; or the sun may 

 heat the soil sufficiently to scorch the young sprouts 

 at or above the surface; or, "finally, the ground may be- 

 come so baked by the sun after a rain, as to prevent 

 smaller seed from breaking through the hard crust. In 

 case of sowing small seeds, like carrot, celery, etc., which 

 are slow to germinate in ground likely to bake, they may 



