I. INTRODUCTION. 

 Lichens, Algae, Tree Bark and Certain Tubers as Foodstuffs. 



From the earliest times, the food of man has included lichens and 

 algae, and even the tender branches and inner bark of certain trees 

 and shrubs, such as elm, birch, pine, and the staff-tree or bitter-sweet 

 {Celastrus scandens). When the bark of trees is so used, it is freed 

 from cork and the hard outer rind; is cleaned, dried, mixed with more 

 or less meal, and made into "bark bread." Such substitutes for 

 bread are commonly resorted to only in northern lands where there is 

 scarcity of cereal crops, or in other regions during periods of famine. 

 Johnson (7) records that elm bark is so employed in some continental 

 countries, and Dillingham (4) relates that certain tribes of North 

 American Indians, 'in times of extreme dearth, were accustomed to 

 keep body and soul together by boiling and eating the bark of the 

 staff-tree.' Poulsson (17) states that in Finland and northern Russia, 

 sphagnum mosses are similarly employed; and Schneider (21) agrees 

 with these other writers, saying that in general lichens are used as 

 articles of diet only in cases of special need, principally because all 

 lichens contain a bitter principle, which not only gives an unpleasant 

 flavor and is difficult to remove, but also exerts an irritating effect 

 upon the digestive tract, causing inflammation. Nevertheless, in the 

 northern parts of the Scandinavian Peninsula, where cereal crops are 

 always scanty or uncertain, great interest attaches to two species of 

 lichen widely distributed through Europe, and through Arctic anc^ 

 Antarctic regions: namely, Celraria islandica and Cetraria nivalis, 

 which, as Poulsson (17) observes, 'have been considered nutritive 

 and easily digestible since olden times. ' Cetraria islandica, whitened 

 and freed from its bitter principle by washing with dilute alkali, is a 

 rather appetizing substance; it has sometimes been used as a foodstuff 

 by Polar navigators, and Dr. Hansteen, chief lecturer in the Agricul- 

 tural school at Aas, Norway, has gone so far as to prophesy that moss 

 is destined to become the great popular food for the masses, because 

 of its cheapness and nutritive properties. 



Of marine algae, many tons are gathered and eaten annually in 

 various parts of the world, the largest quantities being consumed 



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