424 



C. JUDSON HERRICK 



em 



br. conj. 



53 



Fig. 52 Part of a horizontal section through the brain of a 54 mm. larva of 

 Amblystoma prepared by the method of Ramon y Cajal. X 100. The section is 

 somewhat oblique, the right side being farther dorsal. For plane of section, 

 see figure 6. The section illustrates the relatibns of a group of neurones in the 

 base of the cerebellum to the neuropil which receives the ascending secondary vis- 

 ceral tract (Ir.v.a.) and which probably corresponds with the "Rindenknoten" 

 of Mayser in teleosts. For the relations of the termini of VIII root fibers (r. 

 VIII.) in this figure, cf. figure 6. 



Fig. 53 Sketch of a cross section through the medulla oblongata at the level of 

 the VII and VIII roots of a 12 mm. larva of Amblystoma tigrinum. X 74. In the 

 sketch the complete outlines of Mauthner's cells and their chief processes have 

 been reconstructed by the superposition of camera lucida outlines of the seven 

 adjacent sections within which parts of the cell are found, the sections being 5ju 

 thick. 



