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 anæmic. Meanwhile, the group of fat anæmics 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 anæmia, vary in their
constituents. It is not at all unlikely that such is the case, and that,
for example, the fat of an obese anæmic person may differ from that of a
fat and florid person. The flabby, relaxed state of many fat people is
possibly due not alone to peculiarities of the fat, but also to want of
tone and tension in the areolar tissues, which, from all that we now
know of them, may be capable of undergoing changes as marked as those of
muscles.

That, however, animals may take on fat which varies in character is well