Chap. IX. PRELIMINARY REMARKS. 329 



their having practised artificial irrigation 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 were 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, 

 Yespucius and Cabral, describe the country as thickly peopled 

 and cultivated. In North America 16 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 

 different from their parent-stocks ; and escaped seedlings 

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

 perplexity with respect to their specific distinctness and 

 parentage. 17 



Oerealia. — I will now enter on details. The cereals cultivated in 

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

 wheat the best modern authorities 18 make four or five, or even 

 seven distinct species ; of rye, one ; of barley, 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. Eor instance, a 



16 For Canada, see J. Cartier's 17 See, for example, Mr. Hewett C. 



Voyage in 1534 ; for Florida, see Watson's remarks on our wild plums 



iS'arvaez 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 Mons (in his ' Arbres Fruitiers,' 



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



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



pagi;s. See 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. Xov. 1857, p. many aboriginal stocks. 



441. For the traditions of the natives 18 See A. De Candolle, ' Geograph. 



of Xew Zealand, see Crawfurd's Bot.,' 1855, p. 928 et seq. Godror, 



'Grammar and Diet, of the Malay ' De l'Espece,' 1859, torn. ii. p. 70 ; and 



Language,' 1852, p. eclx. Metzger, ' Die Getreidearten,'&c, 1841. 



