PRESERVATION OF RACES BY SEED. 299 



become late and less excitable. Hence, the best 

 seedsmen always take care that their early varieties 

 of annuals are procured from warmer and drier lands 

 than those on which they are to be sown ; our earliest 

 Peas, for example, are obtained from France, and the 

 next in time of ripening from the hot dry fields of 

 Kent, the Suffolk coast, and similar situations. Thus, 

 also, the Barley grown on sandy soils, in the warmest 

 parts of England, is always found by the Scotch 

 farmer, when introduced into his country, to ripen on 

 .his cold hills earlier than his crops of the same kind 

 do, when he uses the seeds of plants which have 

 passed through several successive generations in his 

 colder climate; and Mr. Knight found that the crops 

 of Wheat on some very high and cold ground, which 

 he cultivated, ripened much earlier when he obtained 

 his seed-corn from a very warm district and gravelly 

 soil, which lies a few miles distant, than when he em- 

 ployed the seed of his vicinity. It would seem as if 

 this were in some way connected with the mere size 

 of a seed, the smallest seeds of a given variety pro- 

 ducing plants capable of fructifying quicker than 

 those of a much larger size. We have, at present, 

 but little information upon this subject; but there 

 are some most curious experiments relative to it by 

 Messrs. Edwards and Colin, who found that, although 

 Winter Wheat cannot, in France, be made to shoot 

 into ear, if sown in the spring, provided the largest 

 grains of the variety are employed, yet that, if the 

 smallest grains are picked out, some will ear like 

 Spring Wheat (see Armaks des Sciences Naturahs, v. 



