Kingsbury, Brain of Necturus, 155 



foramen of Monro, and then turns forwards roofing the 

 foramen." 



In the following year Bellonci ('87) published a paper on 

 the anterior commissure in Amphibia and reptiles, in which he 

 states his inability to accept Osborn's conclusions and reaffirms 

 the declaration made in his former papers ('82 and '83) that de- 

 cussational as well as commissural tracts occur in this bundle, his 

 '' tratto supcriore della coniiiiissiira antcriore.'' In the Triton he 

 found the fiber bundles which constitute the dorsal commissure 

 coming from four regions : (i) 'those lobes which in their anter- 

 ior lower and lateral parts contain the olfactory glomerules'; 

 (2) the mesal wall of the hemispheres ; (3) the caudo-lateral 

 part of the same ; and (4), the ' region of transition between 

 the cerebrums and thalami ' and especially from two ganglia 

 dorsad of the portas. 



In 1888 appeared Osborn's paper ('88) containing the fol- 

 lowing comment upon Bellonci's criticism : "I have seen rea- 

 son to partly alter my views as to the nature of the commissures 

 of the hemispheres which were described in detail in my paper 

 on the corpus callosum. The more recent researches of Bel- 

 lonci, with the aid of the Golgi method, upon these commis- 

 sures, should be consulted. They show that with the purely 

 commissural fibers, decussational fibers are intermingled. I 

 have myself discovered that in the upper bundle or corpus cal- 

 losum of MenobrancJms \_Nectiinis\ there enter fibers from the 

 diencephalon." He reaffirms, however, the entire separation 

 of the dorsal bundle from the ventral in Necturus and Proteus. 



With the exception of Bellonci and Herrick (to be men- 

 tioned presently) the investigators following Osborn, — Koppen, 

 Edinger, Burckhardt, Mrs. Gage, and Fish, none of whom ex- 

 cept the last discuss the question to any extent, — all recognize 

 the homology set forth by him. Edinger ('88) states the op- 

 posed views of Osborn and Bellonci without comment, but in 

 his figures names the tract callosum. Burckhardt ('91) seems 

 to have recognized both a callosum and the superior tract of the 

 anterior commissure of Bellonci, not aware apparently that the 

 two are identical. 



