Anemia

The classification of anemia has never been satisfactory. Attempts have been made by various writers to classify the anemias according to the etiologic agents involved. While this is probably the most desirable method, a prerequisite is the discovery of the causative agent, which, in the light of the present inadequate knowledge and methods, is not always possible. From the therapeutic standpoint not only is it useful to know the cause of the anemia, but it is important to differentiate the anemias in accordance with the type of disorder in the hematopoietic system. Such a differentiation, however, is perhaps even more difficult at present than an etiologic classification. As a consequence of this lack of a satisfactory classification, the differentiation in clinical practice of the various forms of anemia is, as a general rule, carried out in an inexact, haphazard manner. The discovery of the use of liver extract and the