EATING WOOD A DIETETIC HABIT.

Dunstan Times, Issue 3138, 9 October 1922, Page 2

EATING WOOD A DIETETIC HABIT.

hi several places on the north coast of Siberia the natives eat wood, not because they must hut because they like it, says the Lancet (London). Wood is generally eaten even when fish is plentiful, their favorite dish being; prepared by scraping ott" thin layers immediately under the bark of larch: logs, chopping them fine and boiling them up with snow. It generally turns out that dietetic habits which at first sight seem curious have a rational basis. The virtues of cod liver oil no longer rest on empirical experience and a vague idea that) its efficacy was proportional to its Hastiness; the reputation of fresh vege-tables-was gained in the days before the Dutch taught us to grow turnips and hardy cabbages, and when something like scurvy was an annual experience of the early spring. It is interesting to guess the reason for wood-eating. The cellulose which forms so large a part of the herbivorous diet is now recognised as being a subsidiary source of energy through the fatty' acids produced in the stomach; and' bowels by cellulose-splitting bacteria But the modified forms of cellulose which form the mass of tree, trunks are hardlv attacked by the bacteria of the alimentary canal. It is possible that the Siberians have by practice and habit so altered their intestinal ttoia that they can deal with lignin with adv.vttt-.vge, but this seems a troublesome way of getting energy when hsli and milk are available, and it appears hardly likely that the explanation of wood-eating lies along these lines. But if the habit suggests at the moment no rationale, it iswnwß to note that it fall's in fine with the tastes ol some other animals. The fondness of rabbite for bark and the immediately subjacent tissues as well known. It is, perhaps, worth noting too that these same invaluable experimental animals are peculiarly fond of hard, woody leaves-as for example, holly, gorse or hawthorn, and sometimes seem actuary to prefer them to cabbage or milk thistle Ponies also are apt to be possessed of a devil or some curious appetite and will set to work on. big forest trees and kill them by cleaning oft the bark and conducting tissues down to the hard wood. These and other examples of similar tastes suggest that there is something particularly good in the outer layers of trees:, and it is natural to think'that it probably resides m the young conducting tissues rather than in the outer bark. Of its precise nature it is idle to speculate.