cartilaginous fishes generally. These conceive a perfect two-coloured egg, made up, that is, of albumen and yelk, and contained in a strong quadrangular shell; from this, still retained within the uterus, the young fish is formed: it then breaks through the shell, and makes its way out. In an exactly similar manner the young viper eats through the egg-shell, sometimes whilst it remains in utero, sometimes when within the passages, at others two or three days after birth. Hence arose the fable of the young viper eating through the womb of its mother, and so avenging its father's death; it does, in fact, nothing but what the young of every animal does, breaking though the membranes which envelope it, either in the delivery itself, or a short time subsequently to that event.
We learn moreover from positive observations how much the fœtus contributes to its own birth. A woman in my own neighbourhood, and I speak as having knowledge of the circumstance, died one evening, and the body was left by itself in a room; the next morning an infant was found between the thighs of the mother, having evidently forced its way out by its own efforts. Gregorius Nymmanus has collected several instances of a similar kind from trustworthy authors.
I am further acquainted with a woman who had the whole length of the vagina so torn and injured in a difficult labour, that subsequently, after she had again become pregnant, not only did the parts in the neighbourhood of the nymphæ, but the whole cavity of the vagina as far as the orifice of the uterus, become adherent; this went to such an extent that coition became impossible, nor could a probe be passed up, nor was there any passage left for the ordinary discharges. When her labour came on her sufferings were so dreadful that all hope of delivery was abandoned. She therefore gave up the keys to her husband, arranged her affairs, and took leave of her friends who were present. On a sudden, however, by the violent efforts of the fœtus the whole space was burst through, and a vigorous infant born; thus was the fœtus the salvation both of itself and its mother, besides opening the way for subsequent children. By the exhibition of proper remedies the mother recovered her former good state of health.
The following instance is even more remarkable. A white mare of great beauty had been presented to her Serene High-
