507 



and the latest stages. As for the earlier stages, I have found the 

 body of the pancreas in several embryos from 20 mm to 35 mm in 

 length extending transversely outward in the (still free) posterior 

 mesogastrium and in contact posteriorly with the kidney, at the lower 

 margin of the suprarenal body. In an embryo 17 mm in length the 

 body of the pancreas was related posteriorly (below the suprarenal 

 body) with the sexual anläge, which separated the pancreas from the 

 kidney. The exact relation of the posterior surface of the pancreas 

 to the suprarenal and kidney in the earlier embryos is subject to 

 much individual variation. The suprarenal body is rapidly enlarging 

 at this period, however, so that it soon spreads downward over the 

 anterior surface of the kidney, shutting out the latter entirely from 

 contact with the pancreas. After this time the posterior surface of 

 the body of the pancreas is found in contact at a variable level with 

 the anterior surface of the suprarenal body, to which it usually 

 becomes adherent during the latter part of the third foetal month. 

 From this time onward the pancreas is found invariably excluded from 

 relation with the kidney until the eighth or ninth foetal month. Then 

 the body of the pancreas is found on the average to lie relatively 

 nearer the inferior margin of the suprarenal body, and often comes in 

 relation with the kidney to a slight extent. The tail of the pancreas 

 is the first part to come into contact with the pancreas at this period, 

 which it does in the angle between the suprarenal body and the lower 

 end of the spleen. In nine cases of foetuses over 40 cm in length 

 which were carefully examined for this point, four, or nearly half, had 

 the tail of the pancreas in contact with the kidney below and behind. 

 It is evident, therefore, that the adult topographic relation is derived 

 from the foetal by the relative retraction of the suprarenal body in a 

 direction from without inwards, during the process of growth, thus 

 allowing the outer portion of the posterior surface of the pancreas 

 to come more and more into contact with the anterior surface of the 

 kidney. 



The intimate relation between the lower surface of the outer 

 extremity or tail of the pancreas and the upper aspect of the splenic 

 flexure of the colon has already been noted. Between the two there 

 extends, in the majority of cases, a well-defined pocket of peritoneum. 

 This pocket, of which I have been able to find no mention in the 

 literature, is a diverticulum from the lesser peritoneal sac, and may 

 be termed the pancreatico-lieno-colic fossa. As shown in 

 Figs. 3 and 4, it is seen, on opening up the lesser sac, as a pocket 

 of crescentic outline, located above the splenic flexure with the tail 



