LOGETIC CHARACTER OF GROWTH 53 



being adapted to the influences of the environment in a rational 

 manner. 



ASSOCIATION (CORRELATION) IN SOMATIC AND MENTAL 

 DEVELOPMENT 



One of the striking factors in the construction of mental con- 

 ceptions is the preponderant role which the simultaneity or direct 

 successivity of stimuli plays in them. This was realized by Aristotle 

 and has always been confirmed. It has also been found that in 

 all forms of association it is the simultaneity of stimuli or residua 

 of stimuli that act the chief part. 



Similarly comparative anatomy of the brain shows that the 

 neurons in the central nervous system 4 always effect connections 

 between two areas, which (even before the neuron joins them) 

 stand to each other in a stimulative correlation, that is to say, 

 which are often simultaneously or successively in a condition of 

 irritation. 



This stimulative correlation — in keeping with the chief law of 

 neurobiotaxis — precedes the anatomic relation (the formation of 

 the neuron which will join them) and this neuronic junction is 

 the result of it. In other words, simultaneous irritations, which 

 repeatedly penetrate into the nervous system" in different places, 

 cause in this nervous system a neuronic association 5 or associative 

 integration between the centers where they arrive. 



This law is for the material development of the nervous system 

 the same as what we have known for centuries as the law of as- 

 sociation in our conscious conceptions (though it was discovered 

 independently of it, without any psychological afterthought). 



Now, if we consider what we observe in the development of a 

 germ-cell into an organism, we find there, too, simultaneously 

 two poles which are conspicuous in the division of the germ cell, 



4 That this also obtains for the peripheral nervous system has been lately 

 proved by Bok in a very ingenious article. Vide Psychiatrische en Neurolo- 

 gische Bladen, 1917, no. 4, "The reflex circle." 



5 What the physicochemical processes are that attend the formation" 1 of this 

 neuronic linking, I cannot discuss here; I beg to refer the reader to The Journal 

 of Comparative Neurology, vol. 27, 1916. 



