No. 144.] 437 



I set apart some square feet of the plants for other experiments, 

 while two of my lots were covered, one with strong poles about 

 ten feet long, another with poles about 7 or 8 feet long. The 

 branches and stalks of the igname twined around these poles as 

 beans do, and soon run beyond the length of their poles. 



In the third lot I let them have their own way, and the vines 

 did not root at their joints, and twisting together, grew nearly as 

 long as those on the poles. 



The tubers which I planted whole gave remarkably vigorous 

 plants, each of which gave a new tuber, of these, two were quite 

 large. When pulled one weighed nearly three pounds (1 kilo. 

 360), the other 1 kilo. 160. The third was injured by the insect 

 Hanneton. The original batatas which I planted were still on, 

 very much wrinkled. The beds of cut tubers did not produce 

 well, weighing on an average not over a quarter of a pound. 



Of the whole, the result was from twenty-eight plants, each 

 giving one tuber; on an average the tubers weighed about five 

 ounces each. (345 qrs. 18.) We found ou the whole from fifty- 

 seven plants, seventeen kilogrammes, or nearly forty-three 

 pounds weight of tubers. 



The result of these experiments shows, that a hectare can pro- 

 duce 6,000 kilogrammes of igname, or that an acre may yield 

 something like two hundred bushels. We think, from what we 

 have seen of the growth, that ten inches apart every way will be 

 room enough for the root— for this plant seems to live upon the 

 air, by its vines and leaves. The product of tubers was nearly 

 double our late usual crop of potatoes. These ignames are from 

 ten to twenty inches long; the upper third of the roots very slen- 

 der, about the size of our little finger. I think that this part 

 should be reserved for planting. The digging of them is a diffi- 

 culty. In China they always plant them in sandy soil. 



I do not hesitate to prefer the Chinese igname to the common 

 potato for quality; I believe the igname to be more nutritious. 

 The flesh of it is as white as snow; it has no apparent fibre in it. 

 By boiling it becomes so tender, that under the lightest pressure 

 it becomes a paste, like that made of the finest wheat flour. 



