Chap. XYlii.] SECRETIONS AND EXCRETIONS IN PARTICULAR. 269 



substances, whose proportion incessantly varies. We find in it 

 a quantity of mineral salts, first of all chlorure of sodium, then 

 chlorure of potassium, chlorohydrate of ammonia, 'sulphates of 

 soda and potash, phosphates of linoie, of soda, of potash, of mag- 

 nesia, ammoniaco-magnesian phosphate, carbonates of lime, of 

 potash. The organic salts and the quaternary products resulting 

 from the disassimilation are lactates of soda, of potash, of lime, 

 urates of Ume, of magnesia, of soda, of potash, of ammonia, a 



Fia. 38. 

 Schematic repreBentetion of a Malpighl glomerule of the bladder :— o, sanguineous vessel 

 entering ; b, sanguineous vessel leaving ; c, clusters of the capillary vessels In the 

 interior of the glomerule ; d, lower part of the capsule drawn without its epithelium ; 

 «, commencement of the urinary canal ; /, internal epithelium of the mass of the capil- 

 laries; g, internal epithelium of the capsule. 



little m-ic acid, and besides, especially in the herbivorous animals, 

 hippui-ic acid and hippurates. Finally, we must add to this 

 long, though incomplete list, the most important products of 

 excretion, urea, creatine, creatinine, immediate principles of the 

 second class derived direct from the oxydation of the albumin- 

 oidal substances in the concatenation of the tissues. 



The composition of urine varies imder the influence of all the 

 causes capable of acting on the nutrition of the animal organism. 



