Royal Society. 487 



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 pulleys 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 

 ganglia. 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 hemorrhoidal 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 off, which pass down on the sides of the 

 vagina, and enter some large flat ganglia, midway between the os 

 uteri and ostium vaginae. 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- 



[* An abstract of this paper appeared in Phil. Mag. S. 3. vol. xvi. p. 590. 

 —Edit.] 



