466 SOIL AFFECTS PEEMANENCE. 



cultivated in a warm dry soil, where it ripens in forty days, will 

 acquire habits of great excitability ; and, when sown in another 

 soil, will, for a season or so, retain its habit of rapid maturity : 

 and the reverse will happen to an annual from a cold wet soU. 

 But, as the latter will gradually become excitable and pre- 

 cocious, if sown for a succession of seasons in a dry warm soil, 

 so will the former lose those habits, and 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 hUls 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 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 employed 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 producing 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 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 Annates des Sciences Naturales, v. 1). Out 

 of 530 grains of Winter Wheat, sown on the 33rd of AprU, and 

 weighing 7 ounces 53 grains, not one pushed into ear, they 

 tillered abundantly, but the tillers were excessively stunted, 

 and concealed among the tufts of leaves ; in short, they formed 

 nothing but turf: on the other hand, of 530 other grains, 



