540 ON PARTURITION.
certain ends, actions, and uses. The structure, then, of the uterus is such, that immediately on conception it shuts up closely its cartilaginous aperture, for the purpose of retaining the seed ; this part subsequently, at birth, and that the fetus may escape, like fruit on the tree, comes to maturity and sof- tens, and this not by any unfolding of its tissue, but by a change in its natural character. For a loosening and softening takes place even in the commissural attachments of bones, as in those between the haunches and the sacrum, the pubes, and the pieces of the coccyx. It is a truly wonderful thing that the little point of a sprouting germ, say of the almond or another fruit, should break the shell which a hammer can scarcely crush ; or that the tender fibres of the ivy-root should pene- trate the narrow chinks of the stone, and at length cause rents in mighty walls. But it does not appear so marvellous that the parts of the woman, when distended by labour, should reco- ver their natural firmness, if we consider the state of the male organ in coition, and how soon it subsequently becomes soft and flaccid. A greater matter for wonder is it, and surpassing all these " foldings," that the substance of the uterus, as the foetus increases, not only is day by day enlarged and distended or unfolded, as it were, to take Fabricius's notion, but that it should become more thick, fleshy, and strong. We may even, with Fabricius, marvel still more at the means by which the mass of the uterus, by the intervention of the ordinary lochial discharges, returns to its original size in so few days ; for this is not the case with other tumours or abscesses ; these require a longer period for dispersion, being made up of unnatural matters, and such as require digestion, a process opposed to the power of expulsion. Yet this is not more worthy of admi- ration than the other works of nature, for " all things are full of God," and the Deity of nature is ever visibly present.
In the last place, it is object of great wonder to Fabricius how those vessels of the foetus (meaning the oval opening out of the vena cava into the pulmonary vein, and the duct from the pulmonary artery into the aorta, on which subjects [ have entered fully in my Essay on the Circulation of the Blood) immediately after birth begin to shrivel up and be- come obliterated. He is driven to that reason given by
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