Kingsbury, Oblongata in Fishes. 3 



Of these two the aqueous formula seemed more satisfactory, 

 although they were not tested for comparative results. With 

 these the stains employed were Delafield's hematoxylin and 

 Van Gieson's picro-fuchsin. The hematoxylin and picro-fuchsin 

 were preferably used separately and all staining was in section. 

 The hematoxylin was used much dilute and allowed to act some 

 time and overstain slightly ; subsequent staining in the picro- 

 fuchsin lasted until all the hematoxylin was removed from the 

 collodion in which all the brains were embedded and cut. An 

 alcoholic i^^'] ^) picro-fuchsin stain was also employed. Wei- 

 gert staining was conducted in the usual manner and these 

 brains were fixed and hardened in 3 and 5 % solutions of potas- 

 sium dichromate several weeks. 



The work was conducted in the Anatomical laboratory of 

 Cornell University, and to the Anatomical Department I am in- 

 debted for much material and all the facilities of research. 

 Professors Wilder and Gage have helped me with their kindly 

 interest, suggestions and advice, and the latter has lent me per- 

 sonal assistance in procuring material ; for all of which I would 

 express my grateful appreciation. All the Acipenser material 

 was obtained and fixed by Dr. O. D. Humphrey of Erie, Pa., 

 and to his care and skill the results obtained were due. 



Of the forms studied, the Ganoids, and Amia in particu- 

 lar, form from every point of view the more natural and conve- 

 nient basis for comparison and point of departure in studying 

 the oblongata of bony fishes. Because of the presence of a 

 cerebellum of typical structure, and the even development of 

 the parts of the oblongata, Amia presents advantages over the 

 simpler urodelan brain on the one hand and the other ganoids 

 (as far as studied) and the teleosts on the other, which present 

 greater though different complexities. Therefore it will be ad- 

 vantageous to discuss somewhat the oblongata and cranial nerves 

 of Amia ; avoiding, however, all details not necessary in con- 

 nection with the purpose of this paper. 



The transition from myel to oblongata in Amia is gradual 

 enough, and the cornua of the cinerea well enough defined (as 

 contrasted with the simpler Necturiis) to permit the following of 



