Chap. IX. WHEAT. 831 



and De Candolle to only four. It is not improbable that, besides 

 the kinds known in Europe, other strongly characterised forms exist 

 in the more distant parts of the world; for Loiseleur-Deskmg- 

 champs 2i speaks of three new species or varieties, sent to Europe 

 in 1822 from Chinese Mongolia, which he considers as being there 

 indigenous. Moorcroft 25 also speaks of Hasora wheat in Ladakh 

 as very peculiar. If those botanists are right who believe that at 

 least seven species of wheat originally existed, then the amount 

 of variation in any important character which wheat has undergone 

 under cultivation has been slight; but if only four or a lesser 

 number of species originally existed, then it is evident that varieties 

 have arisen so strongly marked, that they have been considered by 

 capable judges as specifically distinct. But the impossibility of 

 deciding which forms ought to be ranked as species and which as 

 varieties, makes it useless to specify in detail the differences between 

 the various kinds of wheat. Speaking generally, the organs of 

 vegetation differ little ; 26 but some kinds grow close and upright, 

 whilst others spread and trail along the ground. The straw differs 

 in being more or less hollow, and in quality. The ears 27 differ in 

 colour and in shape, being quadrangular, compressed, or nearly 

 cylindrical ; and the florets differ in their approximation to each 

 other, in their pubescence, and in being more or less elongated. 

 The presence or absence of barbs is a conspicuous difference, and in 

 certain Grammes serves even as a generic character : 28 although, 

 as remarked by Godron, 29 the presence of barbs is variable in certain 

 wild grasses, and especially in those such as Bromus secalinus and 

 Lolium temulentum, which habitually grow mingled with our cereal 

 crops, and which have thus unintentionally been exposed to culture. 

 The grains differ in size, weight, and colour ; in being more or less 

 downy at one end, in being smooth or wrinkled, in being either 

 nearly globular, oval, or elongated; and finally in internal texture, 

 being tender or hard, or even almost horny, and in the proportion 

 of gluten which they contain. 



Nearly all the races or species of wheat vary, as Godron 30 has 

 remarked, in an exactly parallel manner, — in the seed being downy 

 or glabrous, and in colour, — and in the florets being barbed or 

 not barbed, &c. Those who believe that all the kinds are descended 

 from a single wild species may account for this parallel variation 

 by the inheritance of a similar constitution, and a consequent 

 tendency to vary in the same manner ; and those who believe 

 in the general theory of descent with modification may extend this 



24 ' Considerations sur les Cereales,' sid. sur les Cereales,' p. 11. 



1842-43, p. 29. 28 See an excellent review in 



23 'Travels in the Himalayan Pro- Hooker's 'Journ. of Botany,' vol. viii 



rinces,' &c, 1841, vol. i. p. 224. p. 82, note 



26 Col. J. Le Couteur on the 29 " De l'Espece, tom. ii. p. 73. 

 •Varieties of Wheat,' pp. 23, 79. 30 Ibid., tom. ii. 'p. 75. 



27 Loiseleur-Deslongchamps, 'Con- 



