Uniform Standard for Comparative Animal Psychology. 183 



of those peduncles (which he calls "Beihirn") makes 

 up no less than one half of the whole brain. If we take 

 the proportion of weight to volume, we find that almost 

 the same proportion exists between the weight of body 

 and brain in ants, as in dogs, one of the most "in- 

 telligent" species of higher animals; it varies between 

 i :2OO and 1 1300. 



The experiments of scientists whose specialty con- 

 sists in -the anatomy and physiology of the brain, have 

 proved the existence of an essential connection in ver- 

 tebrates between the cerebral cortex and the power of 

 association. Louis Edinger 1 maintains that "all those 

 activities which can be acquired by training, and nearly 

 all those which are performed by the aid of memory 

 images depend on the normal condition of the cerebral 

 cortex" ; and that "all those mental processes which are 

 termed associations are especially connected with it." 

 He repeats the same statement in another- work, 2 and 

 says : "We know for certain that the higher mental 

 functions, and particularly those of an associative nature. 

 are in direct proportion to the normal condition of the 

 brain-cortex." But as the power of association is, 

 according to most modern physiologists, equivalent to 

 "intelligence," this proportional dependence is ex- 

 pressed in (these terms : In the animal kingdom intelli- 

 gence begins with the existence of a cerebral cortex, 

 and with the more perfect development of the cortex 

 a more perfect development of intelligence is necessarily 

 connected. 



*) "Vorlesungen ueber den Bau der nervoesen Centralorgane des 

 Menschen und der Thiere" (5. Aufl., Leipzig, 1896), S. 169. 



2 ) "Neue Studien ueber das Vorderhirn der Reptilien" (Frankfurt 

 a. M~ 1896). S- 6. 



