4 o 4 THE DUCTLESS GLANDS 



and possesses superior, anterior and posterior angles. The 

 superior angle is only ij to 2 inches lateral to the median 

 plane and is on a level with the tenth thoracic spine. The 

 anterior angle lies in the ninth intercostal space in the posterior 

 axillary line, while the posterior angle lies on the eleventh rib. 

 This surface, in its whole extent, is separated by the diaphragm 

 from the lower part of the left pleural sac, and its upper part is 

 also under cover of the lower border of the left lung. Percus- 

 sion of the diaphragmatic surface of the spleen is rendered 

 exceedingly difficult .on account of the number of structures 

 which intervene between it and the surface of the body. They 

 include the diaphragm, the pleural sac, the thoracic parietes, 

 the latissimus dorsi muscle and, over the superior part, the 

 lung and the sacro-spinalis muscle, in addition. It should be 

 remembered that, when the spleen is normal in size and position , 

 it cannot be palpated, as it lies under cover of the left costal 

 margin, and that only its anterior half can be determined by 

 means of percussion. 



The anterior border of the spleen extends from the superior 

 to the anterior angle and it almost invariably possesses one or 

 more notches (Fig. 125). These notches may be of help in 

 determining the nature of a tumour on the left side of the 

 abdomen (vide infra). 



The gastric surface of the spleen is separated from the 

 diaphragmatic surface by the anterior notched border, and 

 from the renal surface by the hilum. The inferior surface of 

 the spleen is in contact with the left flexure of the colon and 

 with a peritoneal fold, termed the phrenico-colic ligament, 

 which extends from the flexure to the diaphragm. This fold 

 is of great importance to the clinician, for it accounts for the 

 direction in which the spleen passes as it enlarges. It prevents 

 enlargement in a purely downward direction, and makes the 

 organ pass forwards and downwards. 



Splenic Enlargement. As the spleen enlarges, the diaphrag- 

 matic surface increases in extent until it projects beyond the 

 costal margin and comes into contact with the muscular anterior 



