Читать книгу The Body at Work: A Treatise on the Principles of Physiology онлайн

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Many attempts have been made to show that if a part of the body has more than its share of food it grows to an excessive size. John Hunter grafted a cock’s spur into its comb. It grew to monstrous dimensions. Such a result favours the view, but it is not quite conclusive. Undoubtedly the comb was richly supplied with blood, but it does not follow that the cells of the spur were able in their new situation to take advantage of this supply. Besides, the spur when projecting from the head was not subject to the accidents to which it was exposed whilst on the leg. Its size was not kept down by friction. Nor was it as hard and compact as it would have been in its normal situation. It is scarcely possible to devise any experiment that would be satisfactory now that the relations between blood and lymph and lymph and tissues are understood. In certain pathological conditions, however, hypertrophy is the result of the hyperæmia of chronic inflammation; and there is little doubt that, if we could arrange for a certain group of cells to receive lymph richer in food and freer from waste products than the perfect adjustment of supply to needs normally allows, the cells would grow.