EXCRETION BY THE KIDNEY. 427 



condition of secretion, though it is likely that this is so chiefly 

 because it favors a rapid renewal of the blood circulating 

 through the organ. Whether there are nerves that influence 

 secretion directly, as in the case of the skin, is not determined. 

 Suppression of the renal functions leads to symptoms in 

 which the nervous system is recognized as suffering to the 

 extent often of coma, ending in death. The urine of most other 

 animals is more concentrated than that of man ; this secretion 

 in carnivora being acid, and in herbivora alkaline in reaction. 



