The Works of William Harvey M.D. / Translated from the Latin with a life of the author

by William Harvey

Of the Acetabula.

Fabricius[389] has ascertained nothing on the subject of the “cotyledons” or “acetabula;” he gives only the various opinions of the ancients. In the former part of my work, however, in the history of the fœtus in the deer, I have mentioned the animals in which acetabula are found; at the same time I described them as constituting numerous cells of a small size scattered throughout the carunculæ, or “fleshy substance,” and filled with an albuminous or mucilaginous fluid, like a honeycomb full of honey.

In the deer they greatly resemble in shape the cavity of the haunch-bone which receives the head of the thigh; hence their name in Greek, κοτυλήδονες (little measures); and in Latin, acetabula, because they resemble the little cups formerly brought to table filled with vinegar for sauce.

These cavities do not exceed in size the holes in a large sponge, and a delicate ramification of the umbilical vessels penetrates deeply into each of them; for in them aliment is laid up for the fœtus, not indeed constituted of blood, as Fabricius would have it, but matter of a mucous character, and greatly resembling the thicker part of the albumen in the egg. Hence it is clear, as I have before observed, that the fœtus in cloven-footed animals (as indeed in all others) is not nourished by the blood of the mother.

Aristotle’s[390] statement, “that the acetabula gradually diminish with the growth of the fœtus, and at last disappear,” is not borne out by experiment; for as the fœtus increases so do the carunculæ; the acetabula at the same time become more capacious and numerous, and more full of the albuminous matter.

If the carunculæ are pressed no blood escapes, but just as water or honey can be squeezed from a sponge or honeycomb, so if pressure is made a whitish fluid oozes from out of the acetabula, which then become shrunk, white, and flaccid, and at last come to resemble a nipple, or a large flabby wart.

Aristotle asserts, with truth, that acetabula are not found in all animals; for they do not exist in the woman, nor (as far as I know) in any animal which possesses a single fleshy substance or placenta. As to the uses of the carunculæ, I believe that, like the mamma, they elaborate not blood but a fluid resembling albumen, and that this serves for the nourishment of the fœtus.

Of the Umbilical Cord.

Fabricius gives an elegant description, as well as most beautiful figures, of the umbilical vessels. “The veins,” he says,[391] “which pass from the uterus in the direction of the fœtus are always closely united and become larger and larger as they proceed; nor does this mutual interlacement cease until all end in two large trunks; these penetrate the fœtus at the umbilicus, and become one vein of great size, which is inserted into the liver of the fœtus, and has a communication both with the vena cava and vena portæ. In like manner the arteries which accompany the veins, being many in number and exceedingly minute, pass from the uterus towards the fœtus, and, gradually uniting and increasing in size, terminate in two large trunks; these, after penetrating the umbilicus, separate from the veins, and attaching themselves to the lateral surface of the bladder by the intervention of a membrane, proceed downwards on either side and become continuous with the branches of the aorta descending to the thigh.” It must be observed, however, that this description of Fabricius applies only to the umbilical vessels of the human fœtus, and not to the young of every animal. Nor even does it hold in the case of the human fœtus except when it is full grown; for at the beginning the arteries make little show, and are so small as to require the eyes of a lynx to see them; nor afterwards indeed are they distinguishable except by their pulsation: in other particulars they resemble veins. Since then, as I have elsewhere shown, the very small branches of arteries do not pulsate, in so far as the eye is concerned, there can be no difference between them and veins. The arteries, I say, at this time are so fine and minute, that they are woven, as it were, like the most delicate threads, into the tissues of the veins, or rather in some obscure manner insinuate themselves into them; hence they almost entirely elude the sight. But all the veins, by a retrograde movement, unite their twigs and terminate in one trunk like the branches of a tree, in the same manner as the mesenteric veins, all of which terminate in the vena portæ.

Near the embryo [the umbilical veins] are divided into two trunks, but when entered within it they constitute one umbilical vein, which ends in the vena cava, near the right auricle of the heart, and passes through the liver, entering the vena portæ; giving off no branches besides until it leaves the convex portion of the liver by a very large orifice. So that if the vena cava is opened from the right auricle downwards and emptied of blood, three apertures may be seen close to each other; one is the entrance of the vena cava descendens, the second that of the hepatic vein, which ramifies throughout the convex portion of the liver, and the third is the origin of the umbilical vein. Hence it is quite clear that the origin of the veins is by no means to be looked for in the liver; inasmuch as the orifice of the vena cava descendens is much larger than the hepatic branch, which is indeed equalled in size by the umbilical vein. For the branches are not said to be the origin of their trunk; but where the trunk is greatest there the origin of the veins is to be looked for, and this is the case at the entrance of the right ventricle: here, then, the origin of all veins, and the storehouse of the blood must be placed.