Graphic illustrations of abortion and the diseases of menstruation / Consisting of Twelve Plates from Drawings Engraved on Stone, and Coloured by Mr. J. Perry, and Two Copper-plates from the Philosophical Transactions, Coloured by the Same Artist. the Whole Representing Forty-five Specimens of Aborted Ova and Adventitious Productions of the Uterus, With Preliminary Observations, Explanations of the Figures and Remarks, Anatomical and Physiological.

by A. B. Granville

44. The membrane having these fibrils on its surface, has been called the Chorion—and from the circumstance that these fibrils, both before the cortex which lies over them has burst, as well as afterwards, serve to promote the nourishment of the fœtus, I have styled it, the nutritive membrane or involucrum of the fœtus. It has been so considered by Ruysch, who calls the villous side of the Chorion, “succosa nutritioni fœtus inserviens.”

45. The fibrils of the Chorion have generally been considered as filiform vessels. When examined with the microscope, they appear diaphanous and ramiform; some of them terminate into little bulbs like the ampullæ of the villosities of the intestines. These bulbs adhere so firmly to the cortex ovi, that when an attempt is made to detach them, many are lacerated. (Carus.) It is only when the cortex bursts of its own accord that they are set at liberty. (43.)

46. These fibrils, however, are not all vessels. Some are only suckers, others are real vessels. (Carus.) The existence of any vessels among the fibrils of the Chorion has been denied very recently upon the same ground, namely, microscopical observations. (Breschet and Raspail.) But there must be an evident mistake in such observations; for the actual progress of those filiform vessels, and their gradual swelling into large veins and arteries, at an advanced period of fœtation, have been noticed in examining various human ova of different ages. (Lobstein, Velpeau, Dutrochet, and myself.)

47. The nutritive envelope or involucrum, or membrane (Chorion) of the Ovum is bifoliated. I have a beautiful preparation of the transparent membranes of the Ovum, even after regular parturition, which proves this fact. It is probably even trifoliated. (Dutrochet.) A fluid has been found between the two laminæ of the Chorion. (Meckel.)

48. The internal surface of the Chorion is likewise supplied with fibrils, which connect it with the next and innermost involucrum of the fœtus, called the Amnion. Between the fibrils or filiform vessels of the two surfaces, a communication is kept up by small vascular trunks which meander between the two laminæ of the Chorion. (Meckel and myself.)

49. The vascularity of the Chorion is further proved by its diseases, chiefly of an inflammatory character, ending in the thickening of its texture. (Plate III., page [12]—Plate IV., page [13]—Plate V., page [17]—and many other examples in this Work.) There is a preparation in Sir Charles Clarke’s collection which shews the vessels of the Chorion as evidently as if they were injected.

50. But the vascularity of the transparent membranes is proved further by fine injections thrown into the vessels of the ovaria of women; on which occasion a beautiful net-work of minute vessels is rendered manifest, forming a species of vascular ring around the Vesiculæ Graafianæ. The same observation has been made by comparative anatomists. (Cuvier, Home, Lobstein.)

51. These facts, demonstrative and corroborative of the vascularity of the Chorion, (45, 46, 48, 49,) explain and account for the reality of that self-existing life-principle inherent in the fecundated Ovum (42), which detaches it from its nest (vesicula Graafiana), enables it to travel through the tube, to grow or expand while thus travelling, and to maintain that same power of growth and development for a short time after its reception into the womb, until its final and effectual implantation on the maternal stock (uterus).

52. The same holds good with regard to the amnion, or inner transparent membrane of the Ovum, which, although normal anatomy has failed, morbid anatomy has succeeded in proving to be vascular. (Plate VI. fig. 20, and Description, p. [19], and Remarks, pp. [20]–24.) (Haller, Monro, Chaussier, Meckel.)

53. If it be true that the amnion is a vascular membrane, there is no difficulty in viewing it also as a secreting membrane. Hence the source of that particular fluid, to which the name of Liquor Amnii has been given, and in which the embryo is suspended to the end of gestation. (Plate I. fig. 4, but particularly fig. 7, 8, and 9, and Remarks.)