146 Wisconsin Academy of Sciences, Arls, and Letters. 



relatively large. In many jEishes the optic lobes alone are 

 larger than the cerebrum. In man, at the other end of the 

 series, the cerebrum is very much larger than all the remaining 

 encephalic ganglia combined. Between these extremes there 

 is every degree of gradation. 



Under this head may be included the suggestion of Dr. Car- 

 penter, that a comparison of the bulk of the cerebrum with the 

 diameter of the spinal cord would give more accurate results 

 than a comparison with the whole body. 



{b) Unsatisfactory as this comparison is in some respects, 

 and inferior as it may be to that suggested by Dr. Carpenter, 

 it yet has much value, and when its results have been care- 

 fully corrected, for density, quality, activity, etc., it will be 

 found fi-ee from most of the objections urged against it. It 

 must not be expected that any one comparison will show all 

 of the truth, especially when the truth is so complex as here. 

 Each one shows its peculiar phase. All must be combined to 

 give all phases and the true result. 



With modifications, the larger the cerebrum, compared ^oith the 

 whole body, the higher the rank. 



General estimates would seem to indicate that the law of the 

 cerebellum, considered individually, is the same, subject how- 

 ever to more important modifications. 



(c) Comparisons of the cerebrum are especially indicative of 

 intelligence. But this is not the only element of the problem. 

 Power of the more physical kind must be computed and com- 

 bined with it to give correct results. Given two animals of 

 equal intelligence, the one which has the gi'eatest muscular 

 power, either quantitative or qualitative, must rank the higher. 

 Comparisons of the encephalic mass and of the entire nervous 

 system must be made, to connect errors arising fi'om this source. 



(e) The size of connecting parts is an additional item bear- 

 ing upon the co-operation of the parts, and taken in connec- 

 tion with what has been said already, and with the fact that 

 the commissures are introduced at different points in the scale. 



