LUMBAR AND SACEAL NERVES AND GANGLIA. 637 



Its position on the fi'ont of the sacrum is along the inner side of the 

 anterior sacral foramina ; and like the two series of those foramina, the 

 two cords approach one another in their progress downwards. The 

 upper end of each is connected with the last lumbar ganglion by a 

 single or a double interganglionic cord ; and at the lower end they are 

 connected by means of a loop with a single median ganglion, ganglion 

 imimr, placed on the fore part of the coccyx. The sacral ganglia are 

 usually five in number ; but the variation both in size and number is 

 more marked in these than in the thoracic or lumbar ganglia. 



Connection with sjnnal nerves. — From the proximity of the sacral 

 ganglia to the spinal nerves at their emergence from the foramina, the 

 communicating branches are very short : there are usually two for each 

 ganglion, and these are in some cases connected with different sacral 

 nerves. The coccygeal nerve communicates with the last sacral, or the 

 coccygeal ganglion. 



Branches. — The branches proceeding from the sacral ganglia are 

 much smaller than those from other ganglia of the cord. They are 

 for the most part expended on the front of the sacrum, and join the 

 corresponding branches from the opposite side. Some filaments from 

 one or two of the first ganglia enter the hypogastric plexus, while 

 others go to form a plexus on the middle sacral artery. From the loop 

 connecting the two cords on which the coccygeal ganglion is formed, 

 filaments are given to the coccyx and the ligaments about it, and to 

 the coccygeal gland. 



Coccygeal Gland. 



Under this name has been described by Luschka a minute structure, 

 which has since received the attention of a number of writers. It is 

 usually, according to Luschka, of the size of a lentil, and sometimes 

 as large as a small pea ; its colour is reddish grey ; its surface lobu- 

 lated ; and it occupies a hollow at the tip of the coccyx, between the 

 tendons attached to that part. It receives terminal twigs of the middle 

 sacral artery and minute filaments from the ganglion impar. It con- 

 sists of an aggregation of grains or lobules, which in some instances 

 remain separate one from another. These lobules are principally 

 composed of thick-walled cavities of vesicular and tubular appearance, 

 described by Luschka and subsequent writers as closed follicles filled 

 with cellular contents, but recently demonstrated by Julius Arnold to be 

 clumps of dilated and tortuous small arteries, with thickened muscular 

 and epithelial coats. Nerve-cells are found scattered in the stroma of 

 the organ. 



The coccygeal gland is a stracture evidently of a similar nature to the ganglion 

 intercaroticum, the pmicipal differences apparently being, that the giomei-uli 

 of the ganglion intercaroticum are produceii principally by the convolution and 

 • ramification of arterial twigs, while in the coccygeal gland there is dilation of 

 the branches and thickening of theii- walls ; and that the nervous element is 

 more developed in the intercarotid ganglion than in the coccygeal gland. Arnold, 

 with Luschka, appears inclined to consider both stractui-es as allied in natm-e to 

 the suprarenal capsules. According to Arnold, there is always a number of small 

 grape-like appendages on the coccygeal part of the middle sacral artery, micro- 

 scopic in size, biit similar in natm-e to the lobules of which the coccygeal gland 

 is composed. (Luschka, •' Der Hirnanhang und die Steissdriise des Menschen." 

 Berlin, 1860. Also " Anat. d. Mensch.," vol. ii. part 2, p. 187. Julius Arnold in 

 Virchow's " Archiv," March, 1865.) 



