AND PORTO SANTO. 115 



448 pounds^ Although three crops of potatoes are to be liad 

 annually in the lower, and two in the upper parts of the island, 

 most of the peasantry remain obstinately attached to, and generally 

 cultivate (merely, as they confess, because their fathers ate it) a 

 species of arum, said to be the cocos of the ^^^est Indies. The leaf 

 answers to Persoon's description of the arum peregrinum ; it is said 

 never to flower here, whether the climate is not warm enough, or 

 whether the mode of cultivation does not favour its fructification. 

 It is very abvindant, and thus managed : a trench is dug and filled 

 with freshly-cut broom, earth is immediately strewed over it, and 

 in that earth is put the root, the tubercle having been taken ofi', 

 and the tops cut ; the few fibres which form the root itself being 

 thus left to propagate it : it requires a great deal of water. The 

 crops are triennial on the hills (that is about 2600 feet above the 

 sea), but annual in the lowest parts of the island. The leaves are 

 so acrid that none but pigs will touch them, and the root is kept a 

 long time before it is cooked. The natives call it inhame, con- 

 sidering it to be a yam. A slice dried in the bath of an alembic 

 lost more than half its weight; and on kneading it in water I 

 found no gluten, but a considerable portion of amidon. The 

 dioscorea alata is cultivated in gardens, but the d. sativa (of 

 Linnaeus) is indigenous; it is good eating, but requires many 

 hours boihng : it only grows on the heights behind Porto Meniz, 

 at the north-west point of the island, and was, until lately, only 

 known to a few of the poorer inhabitants. Perhaps, instead of 

 pronouncing it indigenous, we ought to conclude that some chance 

 has transported it hither. Persoon refers it to India only, and 

 until my arrival in Africa, I cannot ascertain if it also belongs to 



* Potatoes are now cultivated within the Tropics, and in the plains of Siberia ; in 

 Chili, at 11,000 feet above the sea; and in the Environs of Quito, almost under the 

 Equator, at only 1150 feet. See M. Dunal's excellent Monograph on the Genus 

 Solanum. 



Q 2 



