THE CELL AND PROTOPLASM. 129 



so far as secondary problems are concerned. Di- 

 gestion, circulation, respiration, and motion are 

 readily solved upon chemical and mechanical 

 principles. Even the phenomena of the nervous 

 system are, in a measure, capable of comprehen- 

 sion within a mechanical formula, leaving out of 

 account the purely mental phenomena which cer- 

 tainly have not been touched by the investi- 

 gation. All of these phenomena are reducible to 

 a few simple fundamental activities, and these 

 fundamental activities we find manifested by 

 simple bits of living matter unincumbered by the 

 complicated machinery of organisms. With the 

 few fundamental properties of these bits of or- 

 ganic, matter we can construct the complicated 

 life of the higher organism. When we come, 

 however, to study these simple bits of matter, they 

 prove to be anything but simple bits of matter. 

 They, too, are pieces of complicated mechanism 

 whose action we do not even hope to understand. 

 That their action is dependent upon their- ma- 

 chinery is evident enough from the simple de- 

 scription of cell activity which we have noticed. 

 That these fundamental vital properties are to be 

 explained as the result of chemical and mechan- 

 ical forces acting through this machinery, can not 

 be doubted. But how this occurs or what consti- 

 tutes the guiding force which corresponds to the 

 engineer of the machine, we do not know. 



Thus our mechanical explanation of the living 

 machine lacks a foundation. We can understand 

 tolerably well the building of the superstructure, 

 but the foundation stones upon which that struc- 

 ture is built are unintelligible to us. The run- 

 ning of the living machine is thus only in part 

 understood. The living organism is a machine 



