KATABOLISM. 



451 



ance with the law of differentiation, specialization, and 

 localization of functions as we rise in the scale. Both 

 in the embryonic series and in the taxonomic series 

 functions are at first performed everywhere and by all 

 the tissues ; and as we rise in the scale they are more 

 and more separated, localized, and perfected. This one 

 has been gradually more and more localized in the liver. 



