THE study of eclampsia (and the albuminuria of pregnancy) can be carried out from two points of view, the clinical and anzatomnical, which concerns itself with a description and interpretation of the symptoms and the morbid changespresent, and the experimental, in which an attempt is made to reproduce these symptoms and morbid changes in the lower animals. The investigations here recorded were, to begin with, carried out along clinico-anatomical lines. From these preliminary studies there soon emerged an experimental line of inquiry. As a matter of fact, this was entered upon as a necessary test of the validity of the conclusions to which the preliminary investigations had led. Within recent years most of the investigations into the cause of eclampsia have issued from the belief that the placenta is the most likely source of a poison, which all are convinced is the cause of the disease. Therecan be no doubt thatpregnancy is the cause of eclampsia and that the poison is, at any rate, in its ultimate origin to be tracedto the child or to the placenta. That it is not the child is proved by its occurring in cases of hydatid mole, where there is no foetus. This leads inevitably to the conclusion that the direct or indirect source of the poison resides in the chorionic elements. That the relationship between the uterine contents and the toxaemic states is a verydirect one is shown-by their frequent immediate cessation after the emptying ofthe uterus, or after the intra-uterine death of the foetus. On the other hand, even when the child dies in utero, the toxaemia may persist until the child and placenta are delivered. It would in such cases seem clear that the death of the child (the macerated state of which at delivery testifies to the time when this death occurred) must, by the consequent thrombosis of the vessels, prevent any poison which might have been produced in it from being conveyed to the placenta. The placenta, therefore, in such a case, must be the source of the poison; and to my mind, the only