Both arteries and veins enlarge, but the latter increase more rapidly in size than the former, so much so, that even before the descent of the ovum into the uterus, and while the viscus is not itself materially enlarged, the venous system has assumed the appearance of sinews, each branch being larger than a goose quill. Footnote 2: Vide Anatomy of the gravid uterus, with practical inferences relative to pregnancy and labour. Footnote 3: The placenta, contrary to some plans, is not formed exactly at the fundus uteri, stretching equally down on the two faces of the uterus, with the membranes hanging perpendicularly from it. But it lies chiefly on one face of the uterus, whilst the membranes are turned to the other. The centre of the membranous bag, therefore, at this early period, is not directed to the os uteri, but either to the fore or back part of the uterus. In proportion, however, as the bag enlarges, it elongates, its centre, or apex, descends, and ultimately corresponds with the long axis of the uterus. Footnote 4: In some instances, the uterus seems to have the power of forming a vascular substance from its inner surface, although impregnation have not taken place; and, in this case, we may have the symptom of early abortion attending its expulsion. But much oftener we find that this appears as a derangement of the menstrual action, the vessels secreting a semi-organized substance, instead of the usual quantity of bloody fluid; hence, as has been observed by that ingenious and excellent practitioner, Dr. Denman, we have sparing and painful menstruation. Footnote 5: For a fuller explanation and defence of this doctrine, I beg leave to refer the reader to some observations on the animal economy, prefixed to the first volume of my Dissertation on Inflammation. Footnote 6: Vide Dissertations on Inflammation, Vol. I. Footnote 7: This contraction is sometimes so firm after the membranes have burst, as to produce the same effect upon the child, as the natural pains would have done had the pelvis been deformed; that is to say, the presentation becomes unshapely, and the part below the stricture is swelled and livid. This spasm, like that which sometimes retains the placenta, is very difficult to be relaxed, and, in general, requires artificial management. If it come on at the full time, before the membranes break, it may give such a feeling to the lower part of the ovum, as to make it resemble a preternatural presentation, although the head really present. In this case, the band is generally pretty broad, but its contraction is not violent. It has the effect, however, of retarding labour, until we break the membranes, which excites a more general and effective action in the uterine fibres. Footnote 8: