128 THE STORY OF THE LIVING MACHINE. 



and if we can reduce them to an intelligible ex- 

 planation, we may feel that we have really grasped 

 the essence of life. If we understand how the 

 cell can move and grow and reproduce itself, we 

 may rest assured that the other phenomena of 

 life follow as a natural consequence. If, there- 

 fore, we have obtained an understanding of 

 these fundamental vital phenomena, we have 

 accomplished our object of comprehending the 

 life phenomena in our chemical and mechanical 

 laws. 



But have we thus reduced these fundamental 

 phenomena to an intelligible explanation? It 

 must be acknowledged that we have not. We 

 have reduced them to the action of chemical 

 forces acting in a machine. But the machine 

 itself is unintelligible. The organic cell is no 

 more intelligible to us than is the body as a 

 whole. The chemical understanding which we 

 thought we had a few years ago in protoplasm 

 has failed us, and nothing has taken its place 

 We have no conception of what may be the prim- 

 itive life substance. All we can say is that this 

 most marvellous of all natural phenomena occurs 

 only within that peculiar piece of machinery 

 which we call the cell, and that it is the result of 

 the action of physical forces in that machine. 

 How the machine acts, or even the structure of 

 the machine, we are as far from understanding as 

 we were fifty years ago. The solution has re- 

 treated before us even faster than we have ad- 

 vanced toward it. 



Summary. We may now notice in a brief sum- 

 mary the position which we have reached. In 

 our attempt to explain the living organism on the 

 principle of the machine, we are very successful 



