338 CEREAL PLANTS. Chap. IX- 



given by palgeontologists of the first appearance, the increasing 

 rarity, and final extinction or modification of fossil species, 

 eaibedded in the successive stages of a geological formation. 



Finally, every one must judge for himself whether it is 

 more probable that the several foi-ms of wheat, barley, rj-e, 

 and oats are descended from between ten and fifteen species, 

 most of which are now either unknown or extinct, or whether 

 they are descended from between four and eight species, 

 which may have either closely resembled our present cultivated 

 forms, or have been so widely diS'erent as to escape identifica- 

 tion. In this latter case we must conclude that man ciiltivated 

 the cereals at an enormously remote period, and that he 

 formerly practised some degree of selection, which in itself is 

 not'improbable. We may, perhaps, further believe that, when 

 wheat was first cultivated the ears and grains increased 

 quickly in size, in the same manner as the roots of the wild 

 carrot and parsnip are known to increase quickly in bulk 

 under cultivation. 



Maize or Iiidian Corn : Zea mays. — Botanists are nearly unani- 

 mous that all the cultivated kinds belong to the same species. 

 It is undoubtedly ^^ of American origin, and was grown by the 

 aborigines throughout the continent from New England to Chili. 

 Its cultivation must have been extremely ancient, for Tschudi''^ 

 describes two kinds, now extinct or not known in Peru, which were 

 taken from tombs apparently prior to the dynasty of the Incas. 

 But there is even stronger evidence of antiquity, for I found on the 

 coast of Peru ^^ heads of maize, together with eighteen species of 

 recent sea-shell, embedded in a beach which had been upraised at 

 least 85 feet above the level of the sea. In accordance with this 

 ancient cultivation, numerous American varieties have arisen. The 

 aboriginal form has not as yet been discovered in the wild state. 

 A pecuhar kind,*^ in which the grains, instead of being naked, are 



5° See Alph. De Caudolle's long dis- 'Journal of Hort. Soc.,' vol. i., 1846, 



:ussion in his ' Geo.graph. Bot.,' p. 942. p. 115, where an account is given of 



With respect to New England, see Silli- the result of sowing the seed. A 



man's ' American Journal,' vol. xliv. young Guarany Indian, on seeing this 



p. 99. kind of maize, told Auguste St. Hilaire 



51 ' Travels in Peru,' Eng. translat., (^see De Candolle, ' Geograph. Bot.,' p. 



p. 177. 951) that it grew wild in the humid 



^^ ' Geolog. Observ. on S. America,' forests of his native land. Mr. 



1846, p. 49. Teschemacher, in ' Proc. Boston Soc. 



'' This maize is figured in Bonafous' Hist.,' Oct. 19th, 1842, gives an 



magniticcat work, ' Hist. Nat. du account of sowing the seed. 

 Mais, 1836, PL v. bis, and in the 



