Hardestv, Spinal Nerves of the Frog. 



Si 



that the curve begins far below the line of the 1st nerve, rises 

 well above it for the IVth and Vth, falls again for the Vlth, 

 rises highest for the Vllth and ends below the line for the 

 Xth. 



% 



/ // m IV V VI Yii VIII IX. 



Chart III, exhibiting the excess in the larger root of the several spinal 

 nerves. The records show the percentage value of the excess of the larger root. 

 The records for the dorsal root appear above the base line and those for the 

 ventral root, below it. 



3. In regard to the relations existing between the two 

 roots, it can also be shown that during growth the dorsal root 

 fibers increase in number more rapidly than do those of the 

 ventral root [Birge ('82) ]. This is seen to be true even for 

 slight differences in weight. Table II contains a record of 

 counts made of four nerves from a specimen of somewhat greater 

 weight than that entered in Table I. A comparison of the per- 

 centage values of the excess of dorsal root fibers in these four 

 nerves as recorded in the two tables is give in Table VI. 



TABLE VI. 



Number of 

 the nerve 



VI 



VII 



VIII 



IX 



Percentage of excess of dorsal 

 root fibers from records of 



Table I, frog 

 wt. 48.2 grams 



54/0 



Table II, frog 

 wt. 59.52 grams 



214% 

 (>7fc 

 49/e 



