ORIGIN OF RED COEPTTSCLES 



167 



not only enabled to carry oxygen to the tissues but also to 

 remove part of the waste carbon dioxide from them. 



In summary, then, we may say that the two uses to the 

 body of the red corpuscles are the carriage of oxygen to 

 the tissues and the removal of carbon dioxide from them. 



The red corpuscles of man and of all mammals, except 

 the camel family, are biconcave, circular dislcs without 

 nuclei. In the camel family, they are elliptical in shape. 

 They vary, however, in size, and this variation often enables 

 experts to determine the character of blood stains in murder 

 trials. The -red corpuscles of fishes, amphibia, reptiles, 

 and birds are oval in shape and usually nucleated. 



Fig. 59 — Various types of red corpuscles. 



Origin of red corpuscles. — The fact that the human corpuscles 

 are without nuclei shows that they are cells which are in a degen- 

 erating state and hence cannot last long in circul^tipA. Sinpe 



