84 'Journal of Comparative Neurology and Psychology. 



Fig. 5. Transverse section o . 4 mm. caudad of the last, passing through the caudal tip of the median 

 division of the vagal lobe at the point where it passes over into the cephalic end of the visceral commis- 

 sural nucleus. The caudal end of the lateral division of the vagal lobe may be seen two sections farther 

 cephalad in the area here designated substantia gelatinosa. X 35- 



Fig. 6. Transection a little farther caudad through the beginning of the somatic portion of the com- 

 missura infima. The vagal lobes and visceral commissural nucleus lie farther cephalad and the corre- 

 sponding region is here occupied by the somatic commissural nucleus (c/. Fig. 3). The substantia gela- 

 tinosa has begun to enlarge and a little farther caudad (Fig. 7) has expanded into the spinal V nucleus. 

 Short tracts pass between the commissural nucleus and the substantia gelatinosa and formatio reticularis, 

 and secondary tactile paths pass from all of these regions to the ventral cornu and, as internal arcuate 

 fibers, into the ventral commissure. X 35. 



