At all events, the absorption of oxygen diminishes after bleeding, and it used to be well known that some people grew fat when bled at intervals.

Also, it is said that cattle-breeders in some localities--certainly not in this country--bleed their cattle to cause increase of fat in the tissues, or of fat secreted as butter in the milk.

These explanations aid us but little to comprehend what, after all, is only met with in certain persons, and must therefore involve conditions not common to every one who is anaemic.

Meanwhile, the group of fat anaemics is of the utmost clinical interest, as I shall by and by point out more distinctly.
There is a popular idea, which has probably passed from the agriculturist into the common mind of the community, to the effect that human fat varies,--that some fat is wholesome and some unwholesome, that there are good fats and bad fats.

I remember well an old nurse who assured me when I was a student that "some fats is fast and some is fickle, but cod-oil fat is easy squandered." There are more facts in favor of some such idea than I have place for, but as yet we have no distinct chemical knowledge as to whether the fats put on under alcohol or morphia, or rapidly by the use of oils, or pathologically in fatty degenerations, or in anaemia, vary in their constituents.