TRUE RELATION OF SCIENCE TO INDUSTRIES 299 



I *ve seen the largest seeds tho' viewed with care 

 Degenerate unless th' industrious hand 

 Did yearly cull the largest. 



Wheat has been cultivated from the remotest an- 

 tiquity, and without doubt the principles of selection 

 have been practised from the first. It is thus probable 

 that the limit of perfection, as far as selection is con- 

 cerned, has long since been reached. 



The chief value of selections, therefore, at the present 

 time, is to preserve the high standard reached, while 

 the botanist and experimenter must depend on cross- 

 ing and accidental variations for the genesis of new 

 varieties better suited to any given conditions of life. 

 Nevertheless, existing varieties can be gradually ac- 

 climatized when taken to a strange country. In Sierra 

 Leone when wheat was first sown it nearly all ran to 

 leaf. The ears were few and poorly filled. When the 

 seeds of this crop were sown many failed to germinate, 

 but others grew and were much more fertile than the 

 first crop. After a few years the wheat became as fer- 

 tile as in its native country. 



Another striking illustration of the effect of accli- 

 matization in plants is afforded by the chrysanthemum. 

 This plant, which is now so commonly seen, came 

 originally from China. " Introduced into France in 

 1790, it flourished there and produced fruit which it 

 was unable to ripen, so that commerce alone supplied 

 gardeners with the necessary seed for more than sixty 

 years. In 1852 a few plants were observed to flower 

 and to fruit sooner than the others. The seed ripened, 

 and France now produces all the seed which she re- 

 quires." 



Variation in the one species of cabbage has been most 

 remarkable. By careful selection nearly fifty races 



