202 ANTHROPOLOGY. 



on the rectum. It possesses muscular fibres, and a cervical sphincter. The 

 different regions have received different names, as the sujxrior fundus, for 

 the superior anterior extremity ; inferior fundits, the posterior extremity 

 resting on the rectum ; the budi/, the intervening portion ; and the cervix^ the 

 portion connected with the pubes, above the rectum. 



4. The Urethra. The urine is discharged from the bladder by the 

 urethra, a membranous tube, which in the male extends to the extremity of 

 the penis ; and in the female opens into the vagina, behind and below the 

 clitoris. 



The principal constituent of urine is water. When evaporated, the 

 residuum consists principally of urea, uric and hippuric acids ; substances 

 containing a very large amount of nitrogen. Food, mode of life, &c., greatly 

 affect the nature of the urine. The presence of lactic acid is denied by 

 some authors. Extractive matters are present, especially during a vegetable 

 diet, also certain mineral substances, as phosphoric and sulphuric acids, 

 alkaline carbonates, earthy phosphates, and chlorides. The sulphuric acid 

 combinations enter in greatest amount, and to a larger extent, under a 

 purely animal diet, than when the food is more miscellaneous. 



Urine is generally acid ; occasionally, however, it is alkaline, and it 

 always exhibits a conversion of its urea into carbonate of ammonia during 

 putrefaction. Certain substances are readily eliminated from the blood by 

 the kidneys ; others with more difficulty or not at all. Alcohol, sulphuric 

 ether, camphor, musk, and many vegetable colors, arc not removed from the 

 blood. On the other hand, carbonates, sulphates, chlorates, and nitrates of 

 potassa, coloring matter of indigo, musk, castoreum, assafoetida, &c., are 

 entirelv separated. An intermediate class undergoes a transformation before 

 elimination. 



PL 130, fig. 19, exterior of a kidney: ', supra-renal body; ', kidney; 

 '. ureter; '•*, artery and vein. Fig. 20, section of a kidney: ', cortical 

 substance; \ a Malpighian pyramid, composed of uriniferous tubercles and 

 the pyramids of Ferrein, with the papillae; ', a calyx; \ pelvis; \ ureter. 

 Fig. 21, bladder: ', muscular la3'er, with its differently arranged fibres; 

 '',neck of the bladder, with its sphincter muscle ; "> ', ureters ; \ suspensory 

 ligament from the peritonaeum; ", vesicula seminalis; \ prostate gland; 

 ', portion of the urethra. 



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