a rapid advance into unknown territory. There are still many stages to go over again, before we can arrive at a definite picture. A serological examination must be first employed, and the clinical diagnosis, which is generally more uncertain, will be compared with it. Often later observations alone will show, whether the serological diagnosis is really correct. It will be particularly necessary to make our clinical description of individual cases as thorough as possible. The serological diagnosis of diseases of the nervous system will attain a great measure of success, when it enables us to isolate diseases, hitherto considered identical, according to the presence of particular defensive ferments, and to find that the clinical course of the disease corresponds with this. In any event, each separate case must be carefully and continuously studied.
Moreover, the above investigations are of special importance for this reason, that they definitely indicate the specific action of the defensive ferments. Fauser and Wegener report that female patients suffering from dementia præcox never decomposed testes, but only ovaries. Conversely, males only attack testicular tissue, but never the ovary. Both authors have also experimented with placenta, and, on the one hand, confirmed the sero-diagnosis of pregnancy, and on the other showed that the male serum never decomposes tissues of placenta. Of
