The facilities which German investigators have for putting out their more extensive publications in the form of monographs is a source of envy to their American colleagues. Technical and medical journals can not afford to turn over the necessary amount of space for this sort of article, while to attempt to publish independently would be almost inevitably ruinous. In Germany, however, it seems to be possible to float almost any publication, however technical, provided it has merit. Fischer's monograph of 140 pages is one of this class.
In certain conditions we find that organs among whose functions we do not ordinarily consider formation of leucocytes and erythrocytes have taken on this function in circumscribed cellular areas which spring up in various places. This "myeloid metaplasia" we associate especially with leukemia, the finding of so-called lymphoid nodules in the liver and elsewhere being a familiar observation. As Fischer shows, however, this