568 Causes and Course of Organic Evolution 



stimuli, that have very slowly but all the more surely affected 

 its substance. From the brain efferent impulses have pro- 

 ceeded, that have resulted in the diversified "life movements." 



Continued proenvironal seeking out toward new and more 

 varied objects has reflexly stimulated the brain cells and fibers 

 to growth and multiplication. But as many, we might even 

 say most, of the acts in the capuchins and chimpanzees in- 

 volved rapid correlation and resultant selective choice of one 

 amongst several stimuli or groups of stimuli — a position more 

 fully set forth in a succeeding chapter — groups of cognitic 

 stimuli have been linked together in the gray matter of the 

 brain, and have there developed cogitic resultants of a com- 

 pounded character, that have either been stored up as groups of 

 molecular aggregates that constitute memory power, or have 

 in part been expended in the form of active cogitic energy or 

 intelligent acts. 



From our foregoing review of what are biologically the 

 "highest" animals, we therefore conclude that, for increasing 

 tissue complexity, for advancing organization, for more and 

 more elaborate capacity of receiving and responding to en- 

 vironal stimuli, rapid and dominant advance is only effected 

 when the brain and accessory sense centers constantly receive 

 stimulating flows of impressions from without, through mobile 

 and sensitive appendages like the foot-arms of cephalopods; 

 the mandibles, antennae, and forelimbs of ants or bees; the 

 bill and foot of birds; the proboscis of the elephant; the fore- 

 limbs — and head sense-centers more or less — of the beaver, 

 dog, and ape. 



So, as regards their biological dignity, these six or seven 

 groups would be related, as set forth in the diagram, in the 

 ascending ratio of cephalopods, arachnids, birds, beavers, dogs, 

 elephants, ants, and chim])anzees. But many of the ants, as 

 well as to a less degree dogs and beavers, are higher even than 

 some of the apes, in the complexity of their constructive and 

 general biotic-cognitic acts. Such we would attribute to the 

 greatly higher social organization of ants, and to the more 

 primitive though yet advanced social organization of beavers 

 and dogs. 



