56 THE POPULAR SCIENCE MONTHLY 



tions of the brain considered essential to those whose duty it is to bring 

 this organ to its highest state of efficiency. 



For various reasons, which it is not necessary to recapitulate, 

 investigators interested in the study of the functions of the brain have 

 at all times found themselves more or less in conflict with many of the 

 accepted philosophical theories that served to obscure the issues and 

 make progress difficult. King Frederick William's antagonism to the 

 new ideas introduced by science into the study of psychology is a 

 historic example of the difficulties which popular prejudice has created. 

 This sovereign's refusal to believe in the application of the law of cause 

 and effect to the study of mental phenomena, because he would thus be 

 deprived of logical reasons for punishing the deserters from his 

 Grenadier Guards, finds many analogies even at the present day. 



All forms of conduct in the higher as well as the lower organisms 

 are an expression and measure of the functional capacity of the nervous 

 system. From the protozoa -to man we can follow the constantly in- 

 creasing complexity of function as revealed to us in behavior without 

 being able to pick out a single trait as specifically characteristic of any 

 particular organism. Herrick has called attention in a very interest- 

 ing way to the fact that animals widely separated from each other in 

 the scale of functional and structural complexity, as the annelid worms 

 and the vertebrates, present striking differences in behavior referable 

 to the contrasted types of nervous system represented in these two 

 groups. The behavior of the former, stereotyped and predetermined, 

 may be inferred from the structure just as the " plastic individual 

 reactions of the intelligent type " are dependent upon special 

 arrangement of the nervous mechanism of the latter. Between these 

 two extremes are countless gradations in conduct as well as in the 

 arrangement of the nervous system. The prevailing ignorance in 

 regard to facts of the most elementary character relating to the 

 structure and functions of the nervous system is well illustrated by 

 the remarks of an English acquaintance, a graduate of Oxford and a 

 recognized ecclesiastical authority upon matters of conduct, who when 

 told, in reply to an inquiry, that fish had brains, after a brief period of 

 meditation replied, "Beally, that's quite an idea." What a strange 

 comment upon our present methods of education that an individual 

 altogether ignorant of the structural and functional capacity of the 

 brain of a fish, which differs from the human brain only in the simpler 

 arrangement of its elements and the greater limitation of its functions, 

 should be considered an authority upon the training of the most com- 

 plicated nervous system in the whole animal series ! 



The dawn of consciousness, the simplest form of memory, the ele- 

 ment of choice in volitional acts, appear far down in the scale of living 

 creatures, and this law of recapitulation in the behavior of organisms is 



