DoNAtBsoN, Netvous System ef th§ Frog, 533 



XI. Chart 2. 

 Chart showing growth changes in the brain and spinal cord. 



30 



Brain transverse 

 d/a meter . — 



r 



Cord len^tL 



Cord transverse 

 diameter 



20 



10 



Bodj/ weight grms 



\Qo 200 500 



XII. Explanation of Chart. 



In this chart, four cases alone are plotted. The second 

 record in Table 8, being omitted for convenience. One unit 

 of length on the axis of ordinates corresponds with i millimeter 

 in the length of the Brain and Spinal Cord. Ten units are taken 

 to correspond to one millimeter in the transverse diameters. On 

 the axis of abscissas, i unit corresponds to 10 grams of body- 

 weight. In the Chart the curve for the cord's transverse diam- 

 eter has been displaced upwards to prevent confusion. It 

 should begin exactly at 10 and end at 20. 



This curve is to be interpreted as follows : The steeper the 

 curve the greater is the relative increase in size along the axis 



