228 Plant-Breeding 



the plant body, and is not so directly influenced by envi- 

 ronment as are the other organs. And, again, the seed 

 receives a part of its elements from a second or male 

 parent. The good results which follow the use of large 

 seeds are, chiefly, greater uniformity of crop, increased 

 vigor, often a gain in earliness and sometimes in bulk, 

 and usually a greater capacity for the production of 

 seeds. These results are probably associated less with 

 any innate hereditable tendencies than with the mere 

 vegetative strength and uniformness of the large seeds. 

 The large seeds usually germinate more quickly than the 

 small ones, provided both are equally mature, and they 

 push the plantlet on more vigorously. This initial 

 gain, coming at the most critical time in the life of the new 

 individual, is no doubt responsible for very much of the 

 result that follows. The uniformity of crop is the most 

 important advantage which comes of the use of large 

 seeds, and this is obviously the result of the elimination of 

 all seeds of varying degrees of maturity, of incomplete 

 growth and formation, and of low vitality. 



Another important consideration touching the selection 

 of seeds, is the fact that very immature seeds give a feeble 

 but precocious progeny. This has long been observed 

 by gardeners, but Sturtevant, Arthur, and Goff have made 

 a critical examination of the subject. "It is not the 

 slightly, unripe seeds that give a noticeable increase in 

 earliness," according to Arthur, "but very unripe seeds, 

 gathered from fruit (tomatoes) scarcely of full size and 

 still very green. Such seeds do not weigh more than 

 two-thirds as much as those fully ripe. They germinate 

 readily and are more easily affected by retarding or harm- 



