Chap, ao.] The Kidneys. ill. 



is convex, chat placed inwards concave. The kid- 

 neys are varioufly connected to the vifcera, which are 

 next them. The right kidney is connected to the 

 colon, which, as mould have been before remarked, is 

 here partly without the cavity of the abdomen. 



The kidney is made up of. three different fub- 

 ftancesj firft, an external part of a pale colour, which 

 chiefly confifts of numerous convolutions of blood- 

 vefiels, and is called the cortical part. The other 

 two fubftances, that is the medullary or ftriated, and 

 the papillary, are really but one and the fame mafs, 

 of a redder colour. The radiated ilriae are continued 

 into the papillary portion, where they terminate ir> 

 about eleven or twelve papillae, correfponding with 

 the number of glandular portions, of which the kid- 

 ney was originally compofed. At the point of each 

 papilla we fee with the naked eye, in a flight depfef- 

 fion, feveral fmall holes, through which the urine 

 may be perceived to flow when the kidney is com- 

 prefled. Each papilla lies in a kind of membranous 

 calix or (heath, which opens into a common cavity, 

 called the pelvis. The pelvis is alfo membranous, being 

 a continuation of the calix. In man the cavity of the 

 pelvis is not uniform, but diftinguifhed into three por- 

 tions, each of which contains a certain number of 

 calices, together with the papillae which they fur- 

 round. The kidneys are furrounded with a ftrong 

 firm membrane, which is very clofely applied about 

 them. This, however, does not proceed from the 

 peritoneum, but is connected to the pofterior part of 

 that membrane by means of a large quantity of cel- 

 lular fubftance, which is always plentifully filled with 

 fat. 



The urine, which is fecreted in the kidney, drops 



from the papillas into the pelvis. All the fub-divi- 



i fions 



