Chap. IX. rUELIMINAEY REMARKS 329 



their having practised artificial iirigation and made tunnels 

 through hard rocks without the use of iron or gunpowder, 

 and who, as we shall see in a future chapter, fully recognised, 

 as far as animals wore concerned, and therefore probably in 

 the case of plants, the important principle of selection. We 

 owe some plants to Brazil ; and the early voyagers, namely, 

 Vespucius and Cabral, describe the country as thickly peopled 

 and cultivated. In North America ^'^ the natives cultivated 

 maize, pumpkins, gourds, beans, and peas, " all different from 

 ours," and tobacco ; and we are hardly justified in assuming 

 that none of our present plants are descended from these 

 North American forms. Had North America been civilized 

 for as long a period, and as thickly peopled, as Asia or Europe, 

 it is probable that the native vines, walnuts, mulberries, 

 crabs, and plums, would have given rise, after a long course 

 of cultivation, to a multitude of varieties, some extremely 

 difierent from their parent-stocks ; and escaped seedlings 

 would have caused in the New, as in the Old World, uuich 

 perplexity wdth respect to their specific distinctness and 

 parentage. ^^ 



Cerealia.—l will now enter on details. The cereals cultivated in 

 Europe consist of four genera— wheat, rye, barley, and oats. Ot 

 wheat the best modern authorities ^* make four or five, or even 

 seven distinct species; of rye, one; of Ijarley, three; and of oats, 

 two, three, or four species. So that altogether our cereals are 

 ranked by different authors under from ten to fifteen distinct 

 species. These have given rise to a multitude of varieties. It is 

 a remarkable fact that botanists are not universally agreed on the 

 aboriginal parent-form of any one cereal plant. For instance, a 



"^ For Canada, see J. Cartier's " See, for example, Mr. Hewett C. 



Voyage in 1534; for Florida, see Wa+sou's remarks on our wild plums 



Narvaez and Ferdinand de Soto's and cherries and crabs : ' Cybele 



Voyages. As I have consulted these Britannica,' vol. i. pp. 330, 334, &c. 



and other old Voyages in more than Van Mens (iu his ' Arbres Fruitiers,' 



one general collection of Voyages, I 1835, tom. i. p. 444) declares that he 



do not give precise references to the has found the types of all our culti- 



pages. iS'ee also, for several references, vated varieties in wild seedlings, but 



Asa Gray, in the ' American Journal then he looks on these seedlings as so 



of Science,' vol. xxiv. Nov. 1857, p. many aboriginal stocks. 



441. For the traditions of the natives '* /See A. De Candolle, ' Geograph. 



of New Zealand, see C'rawfurd's Bot.,' 1855, p. 928 et seq. Godron, 



'Gramm.ar and Diet, of the Malay ' De I'Espece,' 1859, tom. ii. p. 70 ; and 



LaagTiage,' 1852, p. eels. Metzger, 'DieGetreidearten. &c.. 1841. 



