METABOLISM. 



33 



machine by analysing the silk put into it, and the 

 fabric which comes out, and by taking the specific 

 gravity of its parts and testing the physical 

 properties of its wheels and levers. 



This is not the same thing as denying the value 

 of such knowledge, in the case of either the dead 

 machine or the living plant : it is merely empha- 

 sising the supreme importance of the study of the 

 structure and working of the active machinery in 

 both cases. 



Nor is it pertinent to remark on the apparent 

 hopelessness of physiology being at present able 

 to explain the seemingly infinite complexity of 

 the living machinery of protoplasm and its activi- 

 ties. The modern locomotive is also a complex 

 affair in its way, but it is profitable to investigate 

 it and to know all one can of its working and 

 possibilities, for obvious reasons : a little reflection 

 will convince us that it is also worth while to 

 investigate that complex machine, the plant the 

 working organism which alone can really enrich 

 a country. Moreover, we ought to be encouraged 

 by the satisfactory progress now being made, and 

 the splendid practical results which are accruing, 

 rather than dismayed by the prospect of unflagg- 

 ing labour which will be required in the future. 



Enough has perhaps been said to establish 

 the general truth that the plant is a complex 

 machine for storing energy and material from 

 outside, and we have seen that modern research 

 has at least gone a long way towards determining 

 how the living machine works. 



. c 



