The origin of the cerebral cortex and the homologies of the optic lobe layers in the lower vertebrates

✍ Scribed by Isaac Nakagawa

• Publisher: John Wiley and Sons
• Year: 1890
• Tongue: English
• Weight: 721 KB
• Volume: 4
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1050040102

✦ Synopsis

EDINGER'S discovery of the cortical gray as distinct from the ventricular gray in the Reptilia (1, p. I I I ) leads naturally to the supposition that the rudimentary cortex, if nothing more, must be present in the amphibian cerebrum, in which the mantel is, in its relative size at least, not so very different from that of the reptiles.' And if we are able to find the homologous structure in Amphibia, what is the extent of that homology when we take into comparison the air-breathing vertebrates as a whole ? The first part of this paper contains the result of my observations along that line. The second part consists of investigations directed to determining the homology, and in part the functions, of the several layers described by Osborn and others in the tectum opticum of Rnnn (2, p. 82) in comparison with those of the reptiles and birds.

The researches have been made under the supervision of Professor Osborn in the Class of '77, Biological Laboratory of Princeton College. This is not admitted by Edinger (I, p. 108). "Das erste was an diesen Schnitten auffalt, ist, class keine Spur von einer Hirnrinde zu sehen ist." I