380 Journal of Comparative Neurology. 



elusion that the giant ganglion cells in the spinal cord of at least 

 some Teleosts are directly homologous with the cells in the 

 cord of Amphioxus which give rise to the fibers of the sensory 

 roots. I have made no investigations to determine whether 

 these cells are present in adult specimens of Catostomus or 

 Coregonus, but they seem to be less numerous in the older 

 embryos investigated and they may disappear in the adults. If 

 so, their vestigeal character would perhaps account for the fact 

 that their peripheral processes do not enter the dorsal roots of 

 the spinal nerves, but make their exit nearer the mid-dorsal 

 line. 



It is impossible at present to make any direct comparison 

 of the cells here described with the giant ganglion cells in other 

 fishes, except those described by Tagliani (see above), I shall 

 therefore omit any further review of the literature of giant cells, 

 although giving a list of the papers consulted. The study of 

 the processes of the cells by previous authors has been necessa- 

 rily incomplete on account of the methods employed. Further 

 investigations by the Golgi and methylene blue methods will be 

 necessary before any safe conclusions as to homologies can be 

 reached. 



Morgantoivn, W. Va., Sept. j, igoo. 



PAPERS CONSULTED. 



'92. Beard. The transient Ganglion Cells and their Nerves in Raja batis. 



Anat. Anz., Bd. 7. 

 '96. Beard. The History of a transient Nervous Apparatus in certain Ich- 



thyopsida. Zool. Jahrb , Bd. 9, Heft 2. 

 '97. Dahlgren. The Giant Ganglion Cells in the Spinal Cord of the Order 



Heterosomata Cope (Anacanthini Pleuronectoidei Giinther). Anat. 



Anz., Bd. 13. 

 '77. 'Freud. Ueber den Ursprung der hinteren Nervenwurzeln bei Ammo- 



coetes Planeri. Wien. Sitzungsbericht., Bd. 75. 

 '78. ^Freud. Ueber Spinalganglien undRUckenmark von Petromyzon. Wien. 



Sitzungsbericht., Bd. 78. 

 '96. KoLLIKER. Handbuch der Gewebelehre, Bd. 2. 

 '92. V. Lenhossek. Beobachtungen an den Spinalganglien und dem Riick- 



enmark von Pristiurusembryonen. Anat Anz., Bd. 7. 

 '91. >Retzius. Biol. Untersuch., N. F. Bd. 2. 



These papers I know only from abstracts. 



