38 



Principles of Plant Culture. 



48. The Vigor of the Plantlet is generally in Pro- 

 portion to the Size of the Seed. This is true not only 

 between different kinds of seeds, but between different 



seeds of the 

 same kind. The 

 larger beans, 

 the horse chest- 

 nut and the 

 walnut form 

 much stronger 

 plantlets than 

 clover, timothy 

 and tobacco, 



FIG. 13. Showing navy bean plants grown from and the largest 

 large seeds (left) and from small seeds (right). 



and plumpest 



specimens of any sample of seed usually form stronger 

 plantlets than the smaller and more shrunken specimens. 

 Growers of lettuce under glass are sometimes able to 

 raise one more crop during the winter by sowing 

 only the largest seeds than when the seed is sown with- 

 out sifting. The practice of sifting seeds before plant- 

 ing, and rejecting the smaller ones, should be more 

 generally followed (Fig. 13). 



49. The Earlier Germinations from a sample of seed 

 often Form More Vigorous Seedlings than the Later 

 Ones. This is one of nature's method for preserving 

 the vigor of plants. The stronger seedlings overtop the 

 later and feebler ones and crowd them out of exist- 

 ence. We should profit by this hint and reject the later 

 plants in the seed-bed. 



50. How Deep should Seeds be Planted? We have 

 seen that one object of planting seeds in the soil is to 



