114 evolution: the ages and tomorrow 



to show that evolution has carried forward and upward a 

 simple coordinating property, bringing it out at last in the 

 consciousness of man. In this evolution lies the strength of 

 our mind-in-matter and matter-in-mind thesis— that all the 

 great powers of high intellect can be traced backward 

 through descending levels of mind to their beginnings in 

 unspecialized, unicellular life which could and still does per- 

 form, however slowly and primitively, the greater part of 

 the activities which are seated in the nervous system in 

 higher forms. It was Bergson who pointed out that we need 

 not assume that consciousness necessarily depends on the 

 presence of a nervous system. The nervous system has only 

 "canalized in definite directions, and brought up to a higher 

 degree of intensity, a rudimentary and vague activity, dif- 

 fused throughout the mass of the organized substance."* 



As in the evolution of societies, there is no point at which 

 one can arbitrarily say, "This is where the mind enters." 

 Like all evolutionary series, there is a gradual and impercep- 

 tible rise from primitive beginnings to the present mind of 

 man. In this and the next three chapters it is our purpose to 

 emphasize this oneness of the process; it is most important 

 for us to realize that the mind of man is directly connected 

 to, and is a part of, a continuing evolutionary process. No 

 fundamental understanding of man is possible on the as- 

 sumption that there is, at least in his mind, something new 

 and special. 



In the simplest protozoa, as in the amoeba, the whole 

 body can conduct impulses from a stimulated spot. The 

 communication is slow, but it does make possible a primitive 

 coordination from which has evolved the highly efficient 

 conduction through nerve fibers of the higher animals. In 

 protozoa at a somewhat higher level, as in the flagellates, 

 there is a beginning of differentiation into a sensory region, 

 a zone at the anterior end which is more sensitive than the 



* Henri Bergson, Creative Evolution, trans. Arthur Mitchell (New 

 York: Henry Holt & Co., 1911), p. 110. 



