THE RELATIONS OF THE RETINAL IMAGE TO ANIMAL 



REACTIONS. 



By G. H. PARKER. 

 (Read April 21, ig22.) 



During the past generation the interpretation of animal activities 

 has undergone a profound change. To the earher naturaHsts even 

 the simplest animals were supposed to be endowed with sensations, 

 preferences, desires, volitions, and the like, which, though simplified 

 in form, were nevertheless the same as those in ourselves. But this 

 so-called anthropomorphic viewpoint was soon found to present many 

 difficulties, some of which turned upon new discoveries concerning 

 man himself. It was becoming apparent gradually that human be- 

 ings, in addition to their ordinary mental life, possess a multitude of 

 nervous activities, some of which are subconscious and many of which 

 have no direct relation whatever with consciousness. The more these 

 matters were looked into the more evident it became that our con- 

 scious activities were limited to a special part of our nervous organi- 

 zation, to the brain and perhaps even to the cerebral cortex, and that 

 much of our nervous system had to do with operations quite free 

 from conscious complications. Thus the heart, the blood vessels, the 

 digestive tube, and other like parts, all of which possess their own 

 nervous equipment, exhibit a range of operations of a highly complex 

 and responsive kind that may be entirely dissociated from our con- 

 scious states. As these operations are directed toward the successful 

 continuance of life of the individual in which they occur, we are 

 forced to ask the question, May they not afford an example of the 

 kind of nervous life led by many lower animals whose whole nervous 

 equipment may then be as devoid of the so-called higher nervous 

 states as our heart or our intestines are? An animal thus organized 

 would be merely a delicately adjusted creature without desire, mem- 

 ory, or volition, but responding to changes in its surroundings with 

 as much certainty and precision as our heart or digestive tube does to 



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