Chap. IX. WHEAT. 333 



known to be constant in Spain, which m Germany assumed their 

 proper character only during hot summers ; another variety kept 

 true only in good land, but after having been cultivated for twenty- 

 five years became more constant. He mentions two other sub- 

 varieties which were at first inconstant, but subsequently became ; 

 apparently without any selection, accustomed to their new homes, 

 and retained their proper character. These facts show what small 

 changes in the conditions of life cause variability, and they further 

 show that a variety may become habituated to new conditions. 

 One is at first inclined to conclude with Loiseleur-Deslongchamps, 

 that wheat cultivated in the same country is exposed to remarkably 

 uniform conditions: but manures differ, seed is taken from one 

 soil to another, and, what is far more important, the plants are 

 exposed as little as possible to struggle with other plants, and are 

 thus enabled to exist under diversified conditions. In a state of 

 nature each plant is confined to that particular station and kind 

 of nutriment which it can seize from the other plants by which it 

 is surrounded. 



Wheat quickly assumes new habits of life. The summer and 

 winter kinds were classed by Linnaeus as distinct species ; but 

 M. Monnier 37 has proved that the difference between them is only 

 temporary. He sowed winter-wheat in spring, and out of one 

 hundred plants four alone produced ripe seeds ; these were sown 

 and resown, and in three years plants were reared which ripened 

 all their seed. Conversely, nearly all the plants raised from 

 summer-wheat, which was sown in autumn, perished from frost ; 

 but a few were saved and produced seed, and in three years this 

 summer- variety was converted into a winter- variety. Hence it is not 

 surprising that wheat soon becomes to a certain extent acclimatised, 

 and that seed brought from distant countries and sown in Europe 

 vegetates at first, or even for a considerable period, 38 differently 

 from our European varieties. In Canada the first settlers, accord- 

 ing to Kalm, 39 found their winters too severe for winter-wheat 

 brought from France, and their summers often too short for sum- 

 mer-wheat ; and they thought that their country was useless for 

 corn crops until they procured summer- wheat from the northern 

 parts of Europe, which succeeded well. It is notorious that the 

 proportion of gluten differs much under different climates. The 

 weight of the grain is also quickly affected by climate : Loiseleur- 

 Deslongchamps 40 sowed near Paris 54 varieties, obtained from the 

 South of France and from the Black Sea, and 52 of these yielded 

 seed from 10 to 40 per cent, heavier than the parent-seed. He then 



37 Quoted by Godron, < De l'Espece,' 70. Many other accounts could be 

 vol. ii. p. 74. So it is, according to added. 



Metzger (' Getreidearten,' s. 18), with 39 'Travels in North America,' 



summer and winter barley. 1753-1761, Eng. translat., vol. iii. p. 



38 Loiseleur-Deslongchamps, ' Cere- 165. 



aies,' part ii. p. 224. Le Couteur, p. 40 < Cereal es,' part ii. pp. 170-183 



