78 Journal of Comparative Neurology. 



its fibers from the VII— X anastomosis and the post-auditory 

 lateral Hne root. 



14. The lateral line organs are innervated by components 

 which find their central endings in the acusticum and cerebellum. 



15. The cerebellum is very poorly developed. Fibers 

 from the lobi inferiores are the only ones which enter it from 

 in front. 



16. The Purkinje cells are very slightly developed in the 

 cerebellum and correspond closely to the large cells in the acus- 

 ticum. They send their neurites as internal arcuate fibers to 

 the tectum. 



17. The spindle cells in the acusticum have club-like end- 

 ings of VIII and lateral line VII fibers closely applied to them. 

 The cells do not give rise to Mullerian fibers, but their neu- 

 rites go as internal arcuate fibers to the tectum. 



18. The above facts give the strongest support to the idea 

 of the morphological unity of the acusticum and cerebellum 

 with the nucleus trigemini spinalis and the dorsal horn of the 

 cord. All the cutaneous centers (end-bud center excepted) 

 have been developed from a common Anlage which is the direct 

 continuation and equivalent of the dorsal horn of the cord. 



19. The presence of simple sense organs corresponding 

 to the end-buds of other fishes is confirmed. 



20. These are not very numerous and the fasciculus com- 

 munis system is correspondingly small. 



2 1. There is a fasciculus connnunis VII root which has 

 the same relations as in other fishes. 



22^ The fasciculus communis has a commissura infima 

 Halleri, a median nucleus, and a large ceri/^ical bundle. These 

 structures are probably constant in all vertebrates. 



23. The connnunis center is simpler in structure than in 

 Acipenser. The essential elements seem to be cells of the I 

 type which give rise to a secondary vagus tract. 



24. The tectum opticum presents a much lower grade of 

 differentiation than in other fishes owing to the poor develop- 

 ment of the eyes. The cells serving as a secondary somatic 

 center are similar to those of Acipenser. 



