Page:Proceedings of the Royal Society of London Vol 4.djvu/347

Rh at any angle ; secondly, to the case in which they are equally inclined on either side of the vertical ; thirdly, to the case in which one is horizontal and the other vertical ; and, fourthly, to that in which both are horizontal. He concludes his paper by a deduction from this last case of the modulus of a system of any number of puUeys or sheaves, sustaining among them the weight of any given length of rope horizontally.

3. " On the Nervous Ganglia of the Uterus." By Robert Lee, M.D., F.R.S.

The author, in a paper which was read to the Royal Society on the 1 2th of December, 1839, had described four great plexuses under the peritoneum of the gravid uterus, having an extensive connexion with the hypogastric and spermatic nerves. From their form, co- lour, general distribution, and resemblance to ganglionic plexuses of nerves, and from their branches actually coalescing with those of the hypogastric and spermatic nerves, he was induced to believe, on first discovering them, that they were ganglionic nervous plexuses, and that they constituted the special nervous system of the uterus. He states in the present paper, that subsequent dissections of the unim- pregnated uterus, and of the gravid uterus in the third, fourth, sixth, seventh, and ninth months of pregnancy, have enabled him not only to confirm the accuracy of his former observations, but also to dis- cover the important fact, that there are many large ganglia on the uterine nerves, and on those of the vagina and bladder, which enlarge with the coats, blood-vessels, nerves, and absorbents of the uterus during pregnancy, and which return, after parturition, to their ori- ginal condition before conception took place. The author next pro- ceeds to describe the two great ganglia situated on the sides of the neck of the uterus, in which the hypogastric and several of the sa- cral nerves terminate, and which he calls the hypogastric, or utero- cervical ganglia. In the unimpregnated state, they are of an irre- gular, triangular, or oblong shape, about half an inch in the long diameter, and always consist of grey and white matter, like other gangha. They are covered by the trunks of the vaginal and vesical arteries and veins ; and each ganglion has an artery of considerable size, which enters it near the centre and divides into branches, ac- companying the nerves given off from its anterior and inferior borders. From the inner and posterior surface of each of these ganglia, nerves pass off, which anastomose with the hsemorrhoidal nerves, and ramify on the sides of the vagina, and between the vagina and rectum. From the inferior border of each hypogastric ganglion several fasci- culi of nerves are given ofi", which pass down on the sides of the vagina, and enter some large flat ganglia, midway between the os uteri and ostium vaginse. From these vaginal ganglia innumerable filaments of nerves, on which small flat ganglia are formed, extend to the sphincter, where they are lost in a white dense membranous expansion. From this great web of ganglia and nerves numerous branches are sent to the sides of the bladder, and enter it around the ureter. All these nerves of the vagina are accompanied with arte-