5 o PHYSICAL BASIS OF CIVILIZATION 



In organisms of the type of amoeba, for in- 

 stance, any part of the body is equally capable of 

 attending to any of the principal vital functions, 

 such as capturing food material, enclosing and 

 digesting it, assimilating the fit and excreting the 

 unfit, to locomotion, reproduction, irritation, reflex 

 action, etc. Gradually higher and ever still higher 

 organisms, when fit, have emerged from such low 

 forms through variation and selection. In some of 

 the lower of these forms, which are a little higher, 

 each of the principal vital functions has become 

 segregated and localized in a special part or organ 

 of the body. During the next steps still higher, 

 these principal vital functions begin to be progres- 

 sively subdivided and resubdivided, and each sub- 

 part of a part as it segregates becomes localized in a 

 structure or tissue more and more exclusively adapted 

 to its particular functions only. 



This makes it clear, that the progress of speciali- 

 zation in substance and function is from composite 

 homogeneity throughout to diversity of parts, each 

 of which latter in the highest stages retains only one 

 special kind of the composite material from which 

 it has been segregated. Since function depends on 

 substance, the disentanglement of substance must 

 make progress pari passu with segregation of func- 

 tion. 



A part cannot be equal to the whole. Therefore 

 must the scope of responsiveness to environing 

 substances and conditions, which resides in a sub- 



