56 REVIEWS. 



and vague ; while the evidence against its cultivation by the aborigines 

 appears strong, if not conclusive. If Raleigh found potatoes in North 

 Carolina, they were probably transposed thither by the Spaniards. The 

 potato has not been found wild in any part of the United States, nor was 

 it known to any of the aboriginal tribes before the settlement of Europeans. 

 Such is the joint opinion of Professor Asa Gray, the most competent botanist 

 of America, and of Dr. Harris, Librarian of Havard University, an equally 

 competent authority in questions affecting the early history of America. 

 The Manioc, Manihot, or Tapioca Root (Jatropa Manihot), so important 

 an article of food in the West Indies, is referred to, having been found 

 extensively cultivated at the time of the discovery. It had been erroneously 

 stated by the Abbe Raynal to have been introduced from Africa ; but 

 modern botanists have shown that the genus abounds in species in tropical 

 America, while none have been found wild in tropical Africa, a circum- 

 stance obviously in favour of the American origin of the cultivated kind. 

 Species of Dioscorea or Yam, wild and in cultivation, are found through- 

 out the tropics of both hemispheres, rendering it difficult at the present time 

 to determine what may have been the origin of the cultivated kinds. Not- 

 withstanding their extensive cultivation in India, they have no Sanscrit 

 name. It is disputed whether the name Yam or Igname be of African or 

 of American origin. On the whole, the author refers the probable original 

 centre of Yam -cultivation to the Indian Archipelago and the Southern 

 extremities of Continental Asia. The native country of our common Jeru- 

 salem Artichoke (Helianthus tuberosum) is unknown ; the species is nowhere 

 found in a wild state. It has been known in European gardens from the 

 beginning of the seventeenth century, and Columna, who saw it, in 1616, 

 in the gardens of Cardinal Farnese, names it Aster peruanus tuberosus. 

 Parkinson calls it Batatas canadensis; Bauhin, Chrysanthemum latifo- 

 lium brazilianum. All these names seem to betray an American origin, 

 and De Candolle fixes on the temperate parts of Peru as being the most 

 probable native soil. Hemp and Flax, the earliest cultivated of textile 

 materials, are both referred to the temperate parts of Asia, in the Caucasus, 

 and towards the borders of the Caspian Sea. Hemp is still found wild in 

 Northern India, and Flax in certain districts of Russia ; but it must be 

 extremely difficult to discriminate between the wild and naturalized condi- 

 tion of plants of such early and extensive cultivation. The Sugar Cane 

 is a native of tropical Asia, cultivated from very early times in China, but 

 not anywhere found in a state of nature. It was introduced from Arabia, 

 in the Middle Ages, into Egypt, and thence into Sicily and the South of 



