86 Journal of Comparative Neurology. 



taken just central to the ganglion, or at any point along the 

 course of the roots. This relation is especially presented in 

 Chart IV. This chart is constructed from the data employed 

 for Chart II. It differs from the latter by the fact that the sum 

 of the fibers in the two roots taken just central to the ganglion, 

 is employed instead of plotting the roots separately. The rela- 

 tions presented, therefore, are those of absolute values. The 

 lower curve represents the number of fibers separately contained 

 in the dorsal branches of each nerve. 



Attention is called to the chart as showing (i) the fact that 

 the sum of the roots is always below the sum of the trunk and 

 dorsal branches ; (2) that the curve for the two roots runs near- 

 ly parallel with that of the sum of the trunk and branches ; (3) 

 that the greatest amount of deviation between the two curves 

 does not occur in the larger nerves ; and (4) that the dorsal 

 branches attain their highest absolute values in the smaller 

 nerves. Also, it is to be noted, that, though the value of the 

 dorsal branches does not always coincide with the amount of the 

 excess of fibers which these branches together with the trunk 

 contain above the sum contained in the two roots, yet the curve 

 for the branches suggests that there may exist some relation be- 

 tween the number of fibers contained in them and the amount 

 of the excess. On comparing the percentage values of this 

 excess of the trunk and branches over the sum of the roots for 

 the different nerves, this probability presents itself still more 

 strongly. 



Table XI, here given, is derived from the numbers in 

 Table I and is designed to show first, the amount of the excess 

 of this sum of the trunk and branches over the sum of the roots 

 and the percentage values of the excess based upon the sum of 

 the roots ; and second, the relation or coincidence between this 

 excess and the absolute number of fibers in the dorsal branches. 



