THE HIGHER ORGANISMS 175 



If all these acts can be performed without conscious- 

 ness, what is consciousness, how important is it, and 

 where in the development of the nervous system does it 

 appear? 



Parmelee describes consciousness as "a complex process 

 made up of feelings and ideas which are unified by the 

 sense of personality, which may begin as a vague feeling, 

 but which become, in the course of time, a clear-cut idea." 



It would seem probable that the "vague feelings" 

 might begin low in the animal scale, but the "clear-cut 

 idea" can only be present when the nervous system reaches 

 its maximum development. 



Herrick explains that "consciousness is a functional 

 phase of the more complex mechanism of those higher 

 non-stereotyped actions for which the reflex machinery is 

 inadequate, in much the same way that the tropisms of 

 Paramcecium and the sucking reflex of an infant are 

 functional phases of the simple inborn neuromuscular 

 mechanisms of these organisms." 



Consciousness is best recognized in connection with 

 volition which "manifests itself when the idea of an act, 

 which has grown out of memory images of the act, and 

 other contents of the memory, influence behavior." 



Consciousness can, therefore, be thought to exist when- 

 ever behavior is influenced by ideas or feelings. Like 

 the other phenomena of the central nervous system it is 

 progressive. It begins as a mere "glimmering," as in 

 Crustacea and insects, and is amplified and extended as 

 the structure of the brain improves. It is not a new and 

 suddenly appearing quality peculiar to the highest organ- 

 isms only. 



By slow degrees consciousness evolves into self-con- 

 sciousness. Parmelee explains that this "appears as a 

 result of the process of integration which gives diverse 

 psychic elements a certain unity." 



It is doubtful whether self-consciousness exists apart 

 from the very highest animals. Indeed, it seems to vary 

 so greatly among the races of men as to lead to the suspi- 



