extravasation, or lump of injection, was observed in any part of the intact placenta when cut into. This same result has been obtained, it is understood, in a recent injection by Sir A. Cooper, but the nature of the experiment is not yet known. The same result was obtained by Dr. Hunter, whose positive affirmation has been so recently questioned. The same result has been obtained by Lobstein. The same result has been obtained by Chaussier. Such a result is believed to be correct by Magendie. Professor Mende, in a report to the Obstetrical Society of Gottingen, states having made the experiment of injecting the uterine vessels with air—and with milk, in the case of a woman who died (1830) after the Cæsarean operation, the placenta remaining firmly adherent to the uterus, and he obtained the like result—as Hunter and others. Can we, therefore, refuse credence to such a host of eminent men and experimenters? 86. The decidual vessels derive their fluid from the uterine vessels. The arteries which convey uterine blood to the decidual vessels, are tortuous and very small; they are the adventitious produce of the _membrana propria_ of the womb acting under the influence of a peculiar stimulation which produces the decidual membrane, as inflamed surfaces produce organized exudations. Though the latter be formed in the uterus, even when the embryo is lodged, by aberration, in some other part of the abdomen, its presence must not be deemed, on that account, unessential to the embryo; for a vascular membrane, as nearly alike to it in texture as can be, has invariably been found to connect, by blood-vessels, the embryo to some vital part nearest to where that embryo has been casually deposited, that part having, at the same time, its circulation and vascularity greatly increased, and becoming, in fact, the parent of the connecting vascular membrane in question.