76 URINARY ORGANS. 



vis in front of the rectum. A similar case has been seen by 

 Professor Hensinger.* I have met with several instances of a 

 coalition across the spine, of the two kidneys, so as to present 

 the appearance of a bilobecl organ. 



Of the Excretory Duct of the Kidney, or the Ureter. 



The Ureter is a canal whfch conveys the urine from the kid- 

 ney to the bladder. It commences in the centre of the kidney 

 by an enlargement called pelvis, which branches off' into three 

 or four portions, (calices) one above, one below, and one or two 

 intermediate. Each of these calices, is divided, at its free ex- 

 tremity, into three or four short funnel-shaped terminations, 

 (Infundibula.) Each of these terminations embraces by its ex- 

 panded orifice, the base of a papilla, so as to permit the latter 

 to project into it, and thereby to distil its urine there. Very 

 frequently the number of papillae exceeds that of the infundi- 

 bula, in which case two of the former project into one of the 

 latter. 



The pelvis of the kidney having emerged at the fissure be- 

 hind the vessels, from being expanded and somewhat conoidal 

 in shape is reduced to a cylindrical canal, which, properly 

 speaking, is the ureter: the latter is about the size of a goose- 

 quill, and descends through the lumbar region, between the pe- 

 ritoneum, and the psoas magnus muscle. It dips into the pelvis 

 by crossing in front of the primitive iliac vessels and the inter- 

 nal iliac, crosses the vas deferens at the back of the bladder, 

 and penetrating obliquely the coats of the latter, terminates in 

 an orifice ten or twelve lines behind that of the neck of the 

 bladder. 



The excretory duct of the kidney is formed by two coats. 

 The external is a dense, fibrous, and cellular tissue, but is des- 

 titute of any thing like muscle. The internal is a thin mucous 

 lamina, which can be raised up without much difficulty, and is 

 continuous, at its lower end, with the internal coat of the blad- 

 der; at the upper end, it is supposed by some anatomists to be 

 reflected over the papillae, and even to pass for some distance 

 into the tubuli uriniferi. This duct has considerable powers of 



* Am. Med. Jour. Vol. iii. p. 442. 



