Edible Products. 



520 



[December, 190S. 



was taken to Africa, and probably to 

 the Par East, by the Portuguese. Its 

 spread over the tropics of Africa was 

 rapid, and numerous varieties have been 

 developed there and in Madagascar. 

 There have been several more recent 

 independent introductions into India and 

 Malaya. It has long been grown in a 

 small way in the southern United States, 

 but on a large scale only within the last 

 decade, Within a generation or two it 

 has come into fairly general use by the 

 natives of Hawaii, and has taken the 

 name of '' pia," which to the older inhabi- 

 tants meant arrowroot. There is no 

 record of its introduction into the 

 Philippines, but it is found in limited use 

 throughout the Archipelago, and as the 

 staple crop iu the Islands between 

 Zamboanga and Borneo. 



Varieties and Toxicity. 



It is very probable that, as is true of 

 some other cultivated plants, the culti- 

 vated manioc has several wild ancestor- 

 species, which can no longer be distin- 

 guished. However this may be, a great 

 many varieties are known in cultiva- 

 tion, and many of these have certainly 

 been developed since the plant was 

 domesticated. In Brazil more than fifty 

 varieties are distinguished, most of 

 which are bitter. In Paraguay and in 

 Columbia only sweet varieties are 

 regarded as worth cultivating. In the 

 latter country, twenty-three varieties 

 were collected in a single season for 

 testing in Jamaica ; in which island 

 twenty-two, mostly bitter, varieties 

 were already grown. In German East 

 Africa ten varieties are described. In 

 some parts of India as many as twenty- 

 four varieties are distinguished ; in 

 others, not more than one. At least 

 four each are known in Ceyion and 

 Madagascar; in the United States four 

 varieties were formerly recognized, and 

 a large number have recently been im- 

 ported from Porto Rico and elsewhere, 

 to be tested. In the Philippines there 

 are no varieties distinguished by name, 

 but a considerable difference in toxicity 

 is recognized. 



It is customary to group the varieties 

 as sweet and bitter, and the two groups 

 are often regarded as distinct species. 

 However, no other character has been 

 found which everywhere distinguishes 

 them, moreover there is no line between 

 them, the most and the least bitter 

 being connected by varieties and strains 

 with every intermediate degree of 

 toxicity. Nor is the degree of bitterness 

 a fixed character, but certainly depends 

 upon the environment. Sweet varieties 

 taken from Colombia to Jamaica have 

 almost all become more poisonous with- 



in a few years. On the other haud» 

 varieties taken from Jamaica or Central 

 America or Mexico become sweeter, as 

 also do bitter varieties taken from 

 Jamaica or Porto Rico to Florida. The 

 Guarani Indians of Paraguay claim they 

 have derived their sweet varieties by 

 very long cultivation, from a decidedly 

 poisonous wild ancestor, and that the 

 bitter varieties cultivated by the peoples 

 to their north represent intermediate 

 steps in this development. Prom Florida 

 experiments it seems likely that in the 

 same plant the amount of poison is not 

 at all times the same. In all varieties 

 the thin, dark bark of the root is very 

 poisonous, and the cortex, which as a 

 rule is easily peeled off, also contains a 

 dangerous amount of hydrocyanic acid, 

 It is only the pith which is sweet in 

 some varieties and bitter in others. 



Beside the free hydrocyanic acid, 

 which is in a condition to cause im- 

 mediate poisoning if enough of it is 

 present, there is usually more of the 

 poison combined presumably in the form 

 of a glucoside. When the roots are 

 taken from the ground they very soon 

 beigu to decay, and this glucoside breaks 

 down, setting the hydrocyanic acid free. 

 In this way a wholesome root may with- 

 in a. few days become very dangerous. 

 In New Caledonia the roots are sweet 

 and edible when freshly dug, but fatal 

 even to hogs three days later, and 

 at Manila we have had roots which 

 were perfectly sweet, so far as the 

 senses told, change so much in three 

 days that their grated pulp could not 

 be smelled without acute discomfort 

 The change is usually le^s rapid. 



Uses. 



The manioc roots furnish the chief 

 food of human beings in most parts of 

 tropical America, iu many parts of 

 tropical Africa, and in some parts of 

 Malaya and Polynesia. Roots of sweet 

 varieties are sometimes eaten raw. 

 More commonly, whether they be sweet 

 or bitter, they are boiled or roasted, but 

 as a general rule, meal is made from 

 them. The meal is prepared in various 

 ways. Everywhere, unless it be in 

 Africa, the roots are first crushed by 

 pounding (the primitive American way), 

 rasping (in the Philippines and else- 

 where), or bet, veen rollers. Before the 

 pulp is dried the juice is usually squeezed 

 out of it, but this process wastes con- 

 siderable starch. On the uses and value 

 of this meal, I quote from Dr. James 

 Neish, a physician of Jamaica : — 



The grated pulp, washed and dried, is 

 known under the name of cassava flour 

 or farina when it has been heated and 

 pounced. * * * When reduced into small 



