from both the right and the left side of the brain. The rostral end in all cases 

 is above and the ventral side to the left. 



Fig. 50 Section taken close to the lateral border in the region of the isthmus. 

 Ventrally and rostrally of the cerebellum are the dendrites of a few neurons of 

 the superior secondary visceral nucleus (nuc.vis.s.), which form a dense neuropil. 

 The varicose axons of these neurons are directed forward and ventralward as 

 the tertiary visceral tract (tr.v.t.). These axons cross at right angles the smooth- 

 er axons of the tractus bulbo-tec talis (tr.b.t.). The ascending secondary vis- 

 ceral tract is not impregnated; cf. figure 51. X 30 (cic, 1-1-9). 



Fig. 51 Section slightly farther medial than the last from a different speci- 

 men. In this and the following figures 52 to 55 the plane of section is slightly 

 oblique to the sagittal plane, the dorsal side being farther medial than the ven- 

 tral. The ascending secondary visceral tract (tr.v.a.) ascends along the lateral 

 margin of the oblongata, engages the dendrites of the secondary viscera! nucleus 

 (mic.vis.s.), which are not here impregnated (cf. fig. 50), and passes forward along 

 the ventro-lateral margin of the motor tegmentum. X 30 (U, 24). 



Fig. 52 The adjacent section medialward from the same series as figure 51. 

 The relations of the ascending secondary visceral tract (tr.v.a.) are bst little 



338 



