THE STORY OF NINETEENTH-CENTURY SCIENCE 



red blood corpuscles led, naturally, to renewed studies 

 of these infinitesimal bodies. It was found that they 

 may vary greatly in number at different periods in the 

 life of the same individual, proving that they may be 

 both developed and destroyed in the adult organism. 

 Indeed, extended observations left no reason to doubt 

 that the process of corpuscle formation and destruction 

 may be a perfectly normal one ; that, in short, every 

 red blood corpuscle runs its course and dies like any 

 more elaborate organism. They are formed constantly 

 in the red marrow of bones, and are destroyed in the 

 liver, where they contribute to the formation of the 

 coloring matter of the bile. Whether there are other 

 seats of such manufacture and destruction of the cor- 

 puscles is not yet fully determined. Nor are histolo- 

 gists agreed as to whether the red blood corpuscles 

 themselves are to be regarded as true cells, or merely as 

 fragments of cells budded out from a true cell for a 

 special purpose ; but, in either case, there is not the 

 slightest doubt that the chief function of the red cor- 

 puscle is to carry oxygen. 



If the oxygen is taken to the ultimate cells before 

 combining with the combustibles it is to consume, it 

 goes without saying that these combustibles themselves 

 must be carried there also. Nor could it be in doubt 

 that the chiefest of these ultimate tissues, as regards 

 quantity of fuel required, are the muscles. A general 

 and comprehensive view of the organism includes, then, 

 digestive apparatus and lungs as the channels of fuel- 

 supply ; blood and lymph channels as the transportation 

 system ; and muscle cells, united into muscle fibres, as 

 the consumption furnaces, where fuel is burned and 

 energy transformed and rendered available for the pur- 



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