230 LIFE AND DEATH. 



matter, which is accessory, flows on without a check. 

 This is Cuvier's vital vortex. Rut for what purpose 

 is this circulating matter used ? They thought that 

 it was employed entirely for the reconstitution of 

 the living substance, continually and inevitably de- 

 stroyed by the vital Minotaur. 



Destruction of Reserve-stuff. — Here again there is 

 a mistake. Really living substance is but little 

 destroyed, and consequently requires very little 

 renewal by the functional activity of the animal 

 machine. Its metabolism — destruction and renewal 

 — is in every case infinitely less than is supposed in 

 the classical image of the vital vortex. It is the 

 merit of physiologists, and particularly of Pfliiger and 

 Chauveau, to have worked for nearly forty years 

 to establish this truth. They have proved it, at 

 least as far as the muscular tissue is concerned. 

 Protoplasm, properly so-called, is only destroyed 

 as the organs of a steam engine are destroyed — its 

 tubes, its boiler, its furnace. And it matters little. 

 We know that such an engine uses much coal, and we 

 know very little of its machinery and its metallic 

 frame. And so it is with the cell, the living machine. 

 A very small portion of the food introduced will be 

 assimilated in the living substance. By far the 

 greater part of it is destined to be worked up by the 

 protoplasm and placed in reserve under the form of 

 glycogen, albumen, and fat, etc. — i.e., compounds 

 which are not the really living substance, the hereditary 

 protoplasm, but the products of its industry, just as 

 they are or may be the products of the industry of 

 the chemist working in his laboratory. They will be 

 expended for the purpose of furnishing the necessary 

 energy to the vital functional activity, muscular 



