The Process of Life. 



quantities of available energy resident in highly complex 

 and unstable chemical compounds, elaborated by the 

 constructive energy of the formative protoplasm of its 

 constituent cells. These unstable compounds, eminently 

 explosive according to our analogy, are built up of materials 

 derived from two different sources — from the nutritive 

 matter (containing carbon, hydrogen, and nitrogen) 

 absorbed in the digestive organs, and from oxygen taken 

 up from the air in the lungs. The cells thus become 

 charged with energy that can be.set free on the application 

 of the appropriate stimulus, which may be likened to the 

 spark that fires the explosive. 



Let us note, in conclusion, that it is through the blood- 

 system, ramifying to all parts of the body, and the nerve- 

 system, the ramifications of which are not less perfect, 

 that the larger and higher organisms are knit together into 

 an organic whole. The former carries to the cell the raw 

 materials for the elaboration of its explosive products, 

 and, after the explosions, carries off the waste products 

 ■which result therefrom. The nerve-fibres carry the stimuli 

 by ^vhich the explosive is fired, while the central nervous 

 system organizes, co-ordinates, and controls the explosions, 

 and directs the process of reconstruction of the explosive 

 compounds. 



