4 i 4 DISCOVERY REPORTS 



The posterior parts of the kidneys form rounded bosses when seen in situ, the left 

 considerably more rounded and wider than the right and lying posterior to it (Fig. 22). 

 This rounded outline of the posterior parts of the kidneys is markedly different from 

 their tapering form when extracted. It is due to the fact that the investment of the organ 

 — a reflection of the peritoneum — is more closely attached to the body wall at the hinder 

 end of the kidney than at any other point. Its component fibres run sharply outwards 

 and forwards from this point over the mesal face of the kidney, so that the true posterior 

 end of the kidney, from which the ureter emerges, is pulled round laterally as the 

 kidney increases in bulk and becomes hidden by this stretched portion of the kidney 

 investment. This is seen better on the left than on the right side when the kidneys are 

 observed in situ since the line of attachment of the right organ is more dorsal, so that the 

 kidney overlies the emergence of the ureter in ventral view. 



In consequence of the deflection of the posterior end of the kidney the emergence of 

 the ureter on both sides is seen to be not immediately posterior and apical (Fig. 22), as 

 in the extracted organ, but somewhat lateral — the duct pursuing a short forward course 

 before bending round to its main caudal and inward direction. The ureters on both 

 sides are hidden by a great pad of fibrous tissue, in which they are embedded, and by 

 the peritoneum, which is reflected over them throughout their length. 



The true form of the kidney can only be seen when the whole of the viscera have been 

 removed, including the liver and the stomach (Fig. 22). The right kidney is anterior to 

 the left — its foremost extremity lying rostrally of the tip of the left kidney by about 

 2-0 cm. in a foetus 1-73 m. long. 



The left kidney is roughly semicircular in outline and presents three faces — a broad 

 latero-dorsal one, a latero-ventral and a narrower mesally directed one. The angle 

 between the two lateral faces is rounded ; but the mesal face makes a sharp angle with 

 them, especially anteriorly, where the left lobe of the liver presses against the mesal face 

 of the kidney causing in it a slight incurving. In consequence of this incurving the 

 mesal face of the left kidney takes the form of a backward S in ventral view ; the rostral 

 loop of the S is small and embraces the left lobe of the liver, while the caudal loop is 

 long and gently curved and forms the main mesal face of the organ abutting upon the 

 intestines. 



The right kidney is roughly oval in outline and tapers more markedly than the left. 

 Its greatest breadth occurs about one-third of its length from its anterior extremity. It 

 also presents three faces — a latero-dorsal, a latero-ventral, and a mesal face slightly more 

 ventrally directed than on the other side. The latero-dorsal is the widest of these three 

 faces. Antero-ventrally is a small fourth face, roughly diamond-shaped, caused by the 

 pressure of the stomach against the kidney and also of some of the intestinal coils. On 

 either side of this antero-ventral face the other three faces diminish rostrally to 

 a tip. 



Beauregard and Boulart (1882, p. 61) recognize only two faces to the kidney — a 

 superior and an inferior. They mention, however, a thick external border, which is 

 presumably the latero-ventral face. If this is correct the latero-ventral face must have 



