The Staff-Tree, Celastrus scandens, as a Former Food Supply of Starving Indians

Abstract

IN many kinds of hard and horny seeds there is present, as a reserve material, a carbohydrate which upon hydrolysis yields mannose (a simple sugar closely related to glucose). This carbohydrate has been named mannan. It is one of the hemi-celluloses, a group of substances closely resembling in appearance the true celluloses, but easily resolved into simpler carbohydrates by the hydrolytic action of enzymes or of dilute acids. There is no lack of evidence that mannan which occurs abundantly in the so-called vegetable ivory, Phytelephas macrocarpa, and in the seeds of many other palms, as well as in the wood of coniferous trees, is in spite of its hardness, fit food for camels, neat cattle, sheep, and various rodents. This is illustrated in the girdling of pine trees by mice, as recorded by Thoreau in Walden. ' He says:There were scores of pitch-pines around my house, from one to four inches in diameter, which had been gnawed by mice the previous winter,a Norwegian winter for them, for the snow lay long and deep, and they were obliged to mix a large proportion of pine bark with their other diet. These trees were alive and apparently flourishing at mid-summer, and many of them had grown a foot, though completely girdled; but after another winter such were without exception dead. It is remarkable that a single mouse should thus be allowed a whole pine tree for its dinner, gnawing round instead of up and down it; but perhaps it is necessary in order to thin these trees, which are wont to grow up densely. It is known that the root of a Japanese plant, Conophallus konnjaku, rich in mannan is used as human food, and the question may fairly be asked whether the former use of bark bread by the inhabitants of Scandinavia might not have been dependent upon the mannan in the bark. After discussing this matter in the