Ingbert, Ventral Roots of Spinal Nen>es. 225 



In Fig. 4 is found a comparison between the relative 

 areas of the ventral and dorsal roots of each nerve. In general 

 the two curves are similar — showing that there is the same pro- 

 portional difference between the large and small ventral roots 

 that occurs between the large and small dorsal roots. The 

 largest ventral roots are located further cephalad in the cord 

 than the largest dorsal roots and this is true for both the cervi- 

 cal and lumbar enlargements. 



Moreover, as compared with the curve for the dorsal roots, 

 that for the ventral is distinctly irregular — especially in the in- 

 tumescentiae. 



I nni E Y HYDnn I nmis zh snunix xxixni ninEYiniiHffl 

 CERVICAL THORACIC LUMBAR SACKAL 



Fig. 6. Curves showing the absolute areas of the cross-sections of the ven- 

 tral and the dorsal roots of the left spinal nerves. Each sq. mm. is represented 

 by 20 divisions on the axis of ordinates. 



Fig. 7. Curves showing the number of medullated nerve fibers in the ven- 

 tral and the dorsal roots of the left spinal nerves. Each thousand nerve fibers 

 is represented by two units on the axis of ordinates. 



The accompanying figure 6 represents the absolute areas of 

 the cross-section of the ventral and dorsal roots. Despite the 

 considerable absolute difference, it has just been shown (Fig. 4) 

 that the relative differences are Only slight. 



