3. An hereditary difference has been assumed with reference to the hypoplasia of the red blood corpuscles and slow regeneration of the blood and its hemoglobin contents, but no proof of this difference has been furnished in disputed cases.
Cohnheim ascribes the disposition to accumulate fat under condi tions which are normally without such effect to a faulty activity of the cells, that is, to a slighter energy of the oxidizing processes in the tissue cells, in which it is said the oxygen is combined with the fat supplied to them or occurring as a decomposition product. On the other hand, he leaves it an open question whether the luemoglobin contents of the blood corpuscles are not too low, whereby the oxidiz ing processes are restricted.
Not only in men but also in animals has an hereditary disposition to fat hyperplasia been demonstrated. Iloloff's investigations show that there are certain breeds of swine which are particularly suitable for fattening. This racial _peculiarity is the result of it special mode of breeding which requires not alone an appropriate selection of the brood animals but also uniform and methodical feeding, rest, and fat tening nutriment. When the procedure is continued through many
generations we may observe the interesting fact that the production of fat acquires quite an extraordinary energy, fat in excess accumu lating even in the muscles and the cells of glandular organs, thereby lowering their functions.
Finally the fact deserves special attention that the adipose tissue reacts differently to reducing influences, in cases in which its hyper plasia is due to an hereditary disposition, or has been produced by abundant nutrition or forced feeding. In the latter class it is usu ally possible in a short time to make the excessive fat accumulated in the body undergo combustion by dietetic measures, etc. ; while in the former class this reduction is far more difficult, so that the result is always but temporary in patients who are unable to carry out a suit able mode of life for a tern of years and in whom the prognosis in general is more unfavorable. The varying behavior of fat hyper plasia in hereditary disposition and in acquired corpulence requires for its elucidation a more thorough study.
The hereditary factor is most closely related to the