Page:The Works of William Harvey (part 1 of 2).djvu/639

 and closely sealed, as not to admit a probe, can suffer such distension at the time of delivery. He gives, however, the following reason:

"that the unimpregnated uterus is of a thick and hard consistence, and so is its orifice, but when impregnated is yielding and soft, and in proportion as the term of delivery approaches, both the body of the uterus and its orifice become more and more yielding." He believes this to arise "from the distension which the uterus undergoes, and that when this distension takes place, the compact and plaited, so to speak, body of the uterus is expanded and unfolded; thus what was before thick and hard becomes soft and yielding, and ready to admit of the passage of the fœtus." He adds subsequently, "Some one may ask—if all this is correct, how is it that in pregnant animals the uterine aperture is so closed that it will not admit a probe? I answer, that this is so because the uterus, whilst it is being distended and undone, like a closely-folded piece of linen, begins to undergo these changes at its superior part; the lower portions then gradually widen, until the power of distension arrives at the aperture; this generally takes place at the period of birth. With reason then is the uterine orifice closely shut in the first months of pregnancy, whilst it is still hard and thick, but inclined to dilate in the latter ones. Thus much may be said about the unknown cause of Galen. Other circumstances may be mentioned as conducing to the dilatation of the orifice; for instance, the excretions of the fœtus, such as the sweat and urine; for although these are contained in their proper receptacles and membranes, yet some degree of moisture may be communicated to the uterine aperture, especially as it lies low, and always in the immediate neighbourhood of these humours; added to which, mucous and slimy matters are always found about the orifice." But in my opinion this great man is wrong; for the neck of the uterus is not hard from being folded on itself, but in consequence of its own proper substance and cartilaginous nature; and the accidental causes which he gives can have but little weight towards furthering the dilatation. This, doubtless, like every other contrivance in the human body, is owing to the divine providence of Nature, which directs her workmanship to