602 [Assembly 



two inches, the larger end tapering upwards to the size of the 

 finger, as indicated in the cut above. They are covered by a 

 brownish fawn-colored skin, pierced by numerous rootlets. Under 

 this envelope is a cellular tissue of a white opal color, very crispy, 

 filled with starch, and a milky, mucilaginous fluid, with scarcely 

 any ligneous fibre. In cooking, this tissue softens and dries, but 

 to a greater degree, like that of the common potato, the taste of 

 which it much resembles. Each plant often produces several 

 tubers, though generally it has but one. They usually weigh 

 about half a pound each, but sometimes three pounds, running 

 perpendicularly into the earth, to the depth of a yard. M. Pe- 

 caisne, of France, says, however, jthat those, cultivated by him, 

 rarely exceed 15 to 20 inches in length. 



The cultivation of this yam appears to be easy and simple. 

 M. Decaisne, in the " Revue Horticole," for 1854, has described 

 the method adopted in China, which is nearly as follows : In 

 autumn they choose the smallest tubers, which they preserve from 

 injury by frost, by covering them in a pit with earth and straw. 

 The spring succeeding, they plan^t them near each other in a 

 trench, in well prepared soil. When they have put out shoots, 

 one or two yards in length, they cut off the joints and leaves con- 

 taining the buds, and plant them for reproduction. For this pur- 

 pose, they form the ground into ridges, on the top of which a 

 shallow trench is made with the hand, or some suitable imple- 

 ment, in which these joints are planted, covering them slightly 

 with fine earth, with the leaves rising just on the surface. Should 

 it rain the same day, they shoot immediately ; if not, they water 

 them gently until they do. In fifteen or twenty days, they ^ive 

 birth to new tubers and stalks, the latter of which it is necessary 

 to remove from time to time, to prevent them from taking root on 

 the sides, and thus injure the development of the tubers already 

 formed. 



The method which had been found to answer best in France 

 according to "Le Bon Jardiuier," for 1855, consists in cutting the 

 tubers into fragments of moderate sizd, placing their crowns, or 

 eyes, in small pots, in April, and then transplanting them into a 

 deep, rich soil, as soon as the spring frosts aie no long* r to be 



