Donaldson, Nerve Cell Bodies in the Cortex. 149 



of the dendrons, and thus the gross weight differences between 

 the two sides, tend to be obHterated.^ 



This explanation of the last two instances was put forward 

 by me in 1895,"^ and the correctness of it appears to be the 

 more assured as these newer facts lead to a similar conclusion. 

 It is evident, therefore, that where there are differences in en- 

 cephalic weight determined by the balances, those differences 

 must be further analyzed before they are interpreted, and the 

 absence of a difference as determined by the balances is not 

 evidence that the two parts compared (hemi-cerebrums, for in- 

 stance) are alike in their complexity. 



' Attention is hereby called to the phenomena of variability in the size of 

 axones such as occurs in the encephalon after a part has been removed, the 

 surrounding portions tending to encroach on the cavity by an increase in the 

 mass of the white substance. Also to the change in the diameter of the optic 

 nerve on passing into the sclerotic or the peripheral nerves wherever they are 

 surrounded by a collar of connective tissues and thus'contracted. These changes 

 in mass are not correlated with changes in the cell bodies, or with changes in 

 functional activity. 



2 P. 276. 



