50G ARTERIES. 



The spinal branch, besides supplying offsets which run along the nerves to 

 the dura mater and cauda equina, anastomosing with the other spinal arteries, 

 divides into two branches, one of which ascends on the posterior surface of the 

 body of the vertebra above, and the other descends on the posterior surface of 

 the body of the vertebra below, both vessels anastomosing with similar branches 

 from neighboring spinal arteries. The inosculations of these vessels on each 

 side, throughout the whole length of the spine, form a series of arterial arches 

 behind the bodies of the vertebrae, which are connected with each other, and 

 with a median longitudinal vessel, extending along the middle of the posterior 

 surface of the bodies of the vertebrae, by transverse branches. From these 

 vessels offsets are distributed to the periosteum and bones. 



The abdominal branches pass outwards, behind the Quadratus Lumborum, the 

 lowest branch occasionally in front of that muscle, and, being continued between 

 the abdominal muscles, anastomose with branches of the epigastric and in- 

 ternal mammary in front, the intercostals above, and those of the ilio-lumbar 

 and circumflex iliac below. 



MIDDLE SACRAL ARTERIES. 



The Middle Sacral Artery is a small vessel, about the size of a crow-quill, 

 which arises from the back part of the aorta, just at its bifurcation. It descends 

 upon the last lumbar vertebra, and along the middle line of the front of the 

 sacrum, to the upper part of the coccyx, where it anastomoses with the lateral 

 sacral arteries, and terminates in a minute branch, which runs down to the 

 situation of the body presently to be described as " Luschka's gland." From 

 it, branches arise which run through the meso-rectum, to supply the posterior 

 surface of the rectum. Other branches are given off on each side, which 

 anastomose with the lateral sacral arteries, and send off small offsets which 

 enter the anterior sacral foramina. 



Coccygeal Gland, or Lusclika's Gland. Lying near the tip of the coccyx, in 

 a small tendinous interval formed by the union of the Levator Ani muscles of 

 either side, and just above the coccygeal attachment of the Sphincter Ani, is a 

 small conglobate body, about as large as a lentil or a pea, first described by 

 Luschka, 1 and named by him the coccygeal gland, but the real nature and uses of 

 which are doubtful, nor does it seem at present certain that it always exists. 

 Its most obvious connections are with the arteries of the part. It receives 

 comparatively large branches from the middle and lateral sacral arteries, and 

 its structure, according to Julius Arnold, 2 consists in great measure of dilated 

 arterial vessels. On this account Arnold proposes to call it not a gland, but 

 "glomerulus arterio-coccygeus." It is sometimes single, sometimes formed of 

 several lobes, surrounded by a very definite capsule, into which the sympathetic 

 filaments from the ganglion impar are to be traced, and in which they are said 

 by some observers to terminate. The structure of the body is composed of a 

 number of cavities, which Luschka believes to be glandular follicles, but which 

 are regarded by Arnold as fusiform dilatations of the terminal branches from 

 the middle sacral arteries. Nerves pass into this little body both from the 

 sympathetic and from the fifth sacral, and in the interstices of the lobules nerve- 

 cells are described. 



This body has been variously regarded as an appendage to the nervous or to 

 the arterial system. The former seems to be Luschka's view, the latter is 

 Arnold's. Arnold's view is supported by the observation of Dr. Macalister, 3 



1 Der Hirnanhang und die Steissdriise des Menschen, Berlin, 1860 ; Anatomic des Menschen, 

 Tubingen, 1864, vol. ii. pt. 2, p. 187. 



2 Virchow, Arch., 1864, 5, 6; see also Krause and Meyer in Henle and Pfeiffer's Zeitsch.f. 

 rat. Medizin. 



3 British Medical Journal, Jan. 11, 1868. 



