Europe or W. Asia." On the other hand, Alph. De Candolle (9/20. 'Geograph. Bot.' page 928. The whole subject is discussed with admirable fulness and knowledge.) has adduced abundant evidence that common wheat (Triticum vulgare) has been found wild in various parts of Asia, where it is not likely to have escaped from cultivation: and there is some force in M. Godron's remark, that, supposing these plants to be escaped seedlings (9/21. Godron 'De l'Espece' tome 2 page 72. A few years ago the excellent, though misinterpreted, observations of M. Fabre led many persons to believe that wheat was a modified descendant of Aegilops; but M. Godron (tome 1 page 165) has shown by careful experiments that the first step in the series, viz. Aegilops triticoides, is a hybrid between wheat and Ae. ovata. The frequency with which these hybrids spontaneously arise, and the gradual manner in which the Ae. triticoides becomes converted into true wheat, alone leave any doubt with respect to M. Godron's conclusions.), as they have propagated themselves in a wild state for several generations, their continued resemblance to cultivated wheat renders it probable that the latter has retained its aboriginal character. But the strong tendency to inheritance, which most of the varieties of wheat evince, as we shall presently see, is here greatly undervalued. Much weight must also be attributed to a remark by Professor Hildebrand (9/22. 'Die Verbreitungsmittel der Pflanzen' 1873 page 129.) that when the seeds or fruit of cultivated plants possess qualities disadvantageous to them as a means of distribution, we may feel almost sure that they no longer retain their aboriginal condition. On the other hand, M. De Candolle insists strongly on the frequent occurrence in the Austrian dominions of rye and of one kind of oats in an apparently wild condition. With the exception of these two cases, which however are rather doubtful, and with the exception of two forms of wheat and one of barley, which he believes to have been found truly wild, M. De Candolle does not seem fully satisfied with the other reported discoveries of the parent-forms of our other cereals. With respect to oats, according to Mr. Buckmann (9/23. Report to British Association for 1857 page 207.), the wild English Avena fatua can be converted by a few years of careful cultivation and selection into forms almost identical with two very distinct cultivated races. The whole subject of the origin and specific distinctness of the various cereal plants is a most difficult one; but we shall perhaps be able to judge a little better after considering the amount of variation which wheat has undergone.
Metzger describes seven species of wheat, Godron refers to five, 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-Deslongchamps (9/24. Considerations sur les Cereales' 1842-43 page 29.) speaks of three new species or varieties, sent to Europe in 1822 from Chinese Mongolia, which he considers as being there indigenous. Moorcroft (9/25. 'Travels in the Himalayan Provinces' etc. 1841 volume 1 page 224.) 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 (9/26. Col. J. Le Couteur on the 'Varieties of Wheat' pages 23, 79.); but some kinds grow close and upright, whilst others spread and trail along the ground.