THE SUPRA-RENAL CAPSULES. 527 



I 



and exit of vessels ; this is the hilus lienis. The upper extremity is some- 

 what larger than the lower, and rounded ; the inferior is flattened ; the 

 posterior border is obtuse, the anterior is sharp, and marked by several 

 notches. The spleen is in relation by its external or convex surface with 

 the diaphragm, which separates it from the ninth, tenth, and eleventh ribs; 

 by its concave surface, with the great end of the stomach, the extremity 

 of the pancreas, the gastro-splenic omentum and its vessels, the left kidney 

 and supra-renal capsule, and the left crus of the diaphragm ; by its upper 

 end with the diaphragm, and sometimes with the extremity of the left lobe 

 of the liver ; and, by its lower end, with the left extremity of the transverse 

 arch of the colon. It is connected to the stomach by the gastro-splenic 

 omentum, and by the vessels contained in that duplicature. A second 

 spleen (lien succenturiatus) is sometimes found appended to one of the 

 branches of the splenic artery, near the great end of the stomach ; when 

 it exists, it is round and of small size, rarely larger than a hazel-nut. I 

 have seen two, and even three, of these bodies. The spleen is invested 

 by the peritoneum and by a tunica propria of yellow elastic tissue, which 

 enables it to yield to the greater or less distension of its vessels. The 

 elastic tunic forms sheaths for the vessels in their ramifications through the 

 organ, and from these sheaths small fibrous bands are given off in all di- 

 rections, which become attached to the internal surface of the elastic tunic, 

 and constitute the areolar framework of the spleen. The substance occu- 

 pying the interspaces of this tissue is soft, granular, and of a bright red 

 colour; and frequently . interspersed with small, white, soft corpuscles 

 (Malpighian bodies). These corpuscles, according to the researches of 

 Oesterlen and Mr. Simon, are aggregations of cyto-blasts enclosed in a 

 kind of capsule of capillary vessels. There are, besides, separate cyto- 

 blasts scattered through the red substance. 



Vessels and Nerves. The Splenic artery is of very large size in propor- 

 tion to the bulk of the spleen ; it is a division of the coeliac axis. The 

 branches which enter the spleen are distributed to distinct sections of the 

 organ, and anastomose very sparingly with each other. The veins by their 

 numerous dilatations constitute the principal part of the bulk of the spleen; 

 they pour their blood into the splenic vein, w r hich is one of the two great 

 formative trunks of the portal vein. The lymphatics are remarkable for 

 their number and large size ; they terminate in the lumbar glands. The 

 nerves are, the splenic plexus, derived from the solar plexus. 



THE SUPRA-RENAL CAPSULES. 



The supra-renal capsules are two small yellowish and flattened bodies 

 surmounting the kidneys, and inclining inwards towards the vertebral 

 column. The right is somewhat three-cornered in shape, the left semi- 

 lunar ; they are connected to the kidneys by the common investing areolar 

 tissue, and each capsule is marked on its anterior surface by a fissure 

 which appears to divide it into two lobes. The right supra-renal capsule 

 is closely adherent to the posterior and under surface of the liver, and the 

 left lies in contact with the pancreas. Both capsules rest against the crura 

 of the diaphragm on a level with the tenth dorsal vertebra, and, by their 

 inner border, are in relation with the great splanchnic nerve and semilunar 

 ganglion. They are larger in the fcetus than in the adult, and appear to 



