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IX.—Scottish National Antarctic Expedition: Observations on the Anatomy of 
the Weddell Seal (Leptonychotes Weddelli). By David Hepburn, M.D., C.M., 
Professor of Anatomy, University College, Cardiff (University of Wales). 
ar 11.* 
(MS. received December 4, 1911. Read January 8, 1912. Issued separately January 19, 1912.) 
GENITO-URINARY ORGANS. 
In my former contribution I gave a general summary of the animal under considera- 
tion, and discussed in detail the peritoneal arrangements of its abdominal cavity and 
the naked-eye anatomy of its alimentary organs. In the present paper I shall give an 
account of the genito-urinary system. 
The kidneys were situated on each side of the dorsal mesial mesentery. Hach was 
covered on its ventral aspect by the peritoneum forming the dorsal wall of the greater 
peritoneal sac. The right kidney was quite free from contact with the liver and the 
duodenum, while the left kidney was equally free from contact with the spleen. Both 
kidneys were therefore situated well back towards the pelvic end of the abdominal 
cavity. Hach kidney measured 5 inches in the longitudinal diameter and 2 inches 
in the transverse diameter. The hinder or caudal end of each reached a point two 
inches from the pelvic inlet, which, as formerly described, was narrow and well defined 
by the course of the hypogastric (umbilical) arteries. 
The surface of the kidney indicated lobulation, but the lobules were not separated from 
each other. The hilum was placed ventro-mesially, and at its point of emergence from the 
surface of the kidney the ureter was nearer to the caudal than to the cephalic end of the 
organ. On opening up the hilum, the ureter was seen to result from the union of two main 
tributaries, each of which, in its turn, was formed by the junction of several smaller root- 
lets, which corresponded more or less closely in number to the number of the kidney 
lobules. There was no distinct pelvis to the ureter, which was gradually formed by the 
junction of smaller ducts in the manner indicated. Nevertheless, the widest point of 
_ the ureter was found at the junction of its two main tributaries. The ureter and its 
chief tributaries lay on the ventral (anterior) aspect of the renal vessels, and not on their 
dorsal (posterior) aspect, as is the case in man. 
The size of the ureter suggested a vessel about half the diameter of an average 
_ human radial artery. The ureter followed a course along the dorsal wall of the abdomen 
_ towards the pelvic inlet; and half an inch beyond the termination of the abdominal 
aorta, or, in other words, at the point where the common iliac artery divided into its 
external and internal branches, the ureter crossed to the mesial side of the internal iliac 
and hypogastric arteries, and continued its course along the margin of the pelvic inlet. 
In this position the ureter and the hypogastric artery were both in their turn crossed 
* Part I. was published in the Trans. Roy. Soc. Edin., vol. xlvii., pt. i. (No. 3), 1909. 
TRANS. ROY. SOC. EDIN., VOL. XLVIII. PART I. (NO. 9). 30 
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