202 ELIMINA TION 



but it must be slow indeed compared with the desqua- 

 mation of liver and kidney cells that must take place 

 if the bile and urine discharged are set free by the 

 rupture and destruction of epithelial particles. But 

 what shall we say concerning the gastric juice, in 

 which case many pounds of secretion are poured out 

 in the course of twenty-four hours from glands which, 

 with their vessels and other structures included, weigh 

 but a few ounces ? Does the formation of every drop 

 of gastric juice necessitate the destruction of an equal 

 bulk of gland cells ? Is it not much more probable 

 that the secretion filters away fully formed from the 

 gland cell as fast as it is produced, while the latter 

 remains apparently unchanged ? In the case of the 

 cuticular cell, it is necessary to inquire if the hard 

 epithelial material is the only thing eliminated by its 

 agency. Was it not very moist at an early period of 

 its life, and is it not probable that much liquid hold- 

 ing various soluble substances in solution filtered 

 through it and was carried ofif for a long time before 

 the cell itself was cast away ? 



If the formation of a liquid secretion, like the bile, 

 urine, or gastric juice, involved the growth and de- 

 struction of epithelial cells, the quantity of the secre- 

 tion formed in these cases is so very great that the 

 growth of the cells would take place very quickly. I 

 think that we ought to be able to see, under our 

 microscopes, the actual process of growth taking 

 place if not in man, at least in some of the lower 



