608 THE POSTERIOR PITUITARY AND THE NERVOUS SYSTEM. 



reached its maturity; but the fact that they are at all subject 

 to development proves their identity as parts of the whole, and 

 though endowed with sovereignty over all functions, they stand 

 no higher than any other organ as a life-center, though perhaps 

 the seat of inordinate metabolism. 



Oxygen, we have seen, is the active agency through which 

 the anterior lobe carries on its functions; phosphorus is that 

 upon which the posterior lobe depends with the oxidizing 

 substance of the plasma for the elaboration of its intrinsic 

 energy. These two elements underlie the functional activity 

 of all cells, and their mutual affinity accounts for the display 

 of vital energy of which all cellular structures are the seat. 

 Oxygen-laden blood brought into contact with phosphorus- 

 laden cells of which all tissues are built represents, therefore, 

 the foundation of functional activity. Indeed, Pfliiger, 64 re- 

 ferring to the photogenic organs of lightning-bugs, says: "Here, 

 in the wonderful spectacle of animal phosphorescence, Nature 

 has given us an example that shows where the taper burns that 

 we call life. . . . It is certainly no rare exception, but only 

 the special expression of the general law, that all cells are 

 burning continually, although with our corporeal eyes we do 

 not see the light." 



64 Pfliiger: "General Physiology," by M. Verworn; translated by F. S. Lee, 

 1899. 



