496 THE GARDEN AND ITS FKTJITS. [Chap. V. 



appears among the roots a soft, fleshy horn, which directs itself perpendicu- 

 larly downward, and growing with considerable rapidity, soon becomes a 

 club-shaped body, the small end of which is near the surface of the ground. 

 Tliis manner of growth is exactly like that of the arrow-root plant {Marantu 

 arundhiacea), and continues until the end of October, when the yam is 

 completed, and under proper treatment will have attained the length of from 

 15 to 24 inches, weighing about one pound. In Franco, specimens have 

 been dug up weighing two and a half pounds, and measuring a yard in 

 length. In its perfect state it resembles a very long trumpet gourd or a 

 large parsnep, with the crown downward. The tail, which forms one third 

 of the length, is cut off and divided into inch lengths for propagation ; the 

 thicker part is eaten. In the course of its downward growth, the power of 

 development is so great that the thick end will force its way into hard clay, 

 and even bury stones or fragments of jjottery in its substance if its progress 

 is sufficiently ojiposed. All obstacles ought to be carefully removed. 



The best results in the cultivation of this yam have been obtained where 

 tlio temperature was highest, and the first object of the gardener should be to 

 obtain all the heat the sun can give him in soil three feet deep. 



The plant should be grown in ridges, made to run east and west, and rise 

 eighteen inches above the level, in earth trenched three feet deep. The yam 

 will not be worth growing in poor or worn-out land, nor among stones. 



There is no doubt of one beneficial result from the attempt to cultivate 

 this root, if the above directions are complied with. If it does not jiroduce 

 a profitable crop of yams, it M'ill fit the ground most admirably for any other 

 crop ; and any man who has ever planted, grown, and gathered them, and 

 afterward planted any other crop upon the same ground, must be convinced 

 of the advantage of deep cultivation, since the yams can not be extracted 

 without digging two or three feet deep, which, even without manure, is a 

 most excellent preparation for beets, carrots, parsneps, or anytiiing else ever 

 grown upon the farm, orchards included. 



.565. Sweet Potatoes. — The first step in the cultivation of sweet potatoes is 

 to know how to sprout them, as they are grown from sets, not from tubers 

 planted in the hill. J. W. Tenbrook, of Rockville, Ind., published the fol- 

 lowing directions, which we copy and apjjrove. 



" Arrangements should be made early in the winter to have frames and 

 covers made and seed potatoes, manure, and all necessary material for the 

 hot-beds ready in due time. 



" The potatoes should be kept in a warm, dry i-oom, until they are placed 

 in the hot-bed, which must be warm, as they will not bear a lower tempera- 

 ture than 40 degrees without injury. 



" The location of the beds should be near a street or public road, on dry 

 ground, with a southern inclination, and convenient to pond or branch 

 water. 



" The best material for a hot-bed is fresh horse-stable manure that has not 

 been rotted ; and if mixed with one fourth to one half its bulk of either 



