clxii Journal of Comparative Neurology. 



of the tela. " He supports his conclusion also from the previous pub- 

 lications both of Mrs. Gage on Diemyctylus and Amia and of C. L. 

 Herrick on the ganoids and teleosts. 



In a short paper before the Anatomische Gesellschaft 1 the same 

 author continues the discussion of the significance of the palhum, es- 

 pecially in Petromyzon. He repeats the statement made in his first 

 paper that the hemispheres here correspond only to the hindermost 

 part of the hemispheres of higher animals, taking Edinger's ground 

 that it is exclusively an olfactory centre. In support of his belief that 

 the pallium is a " tela" or paraphysis, he figures a section of the Pe- 

 tromyzon brain, showing between the hemispheres and the pallium a 

 massive part in the proper position for the fornix. 



In a final paper 2 Burckhardt has brought together the main 

 points of his earlier communications, together with some additional 

 matter. The paper is in effect a very practical plea for the proper 

 recognition of the morphological importance of the membranous por- 

 tions of the encephalic walls. Following His, with some modifica- 

 tions, he divides the brain into the following longitudinal zones : 



i. The base-plate (Bodenplatte), the ventral median line. This 

 long remains membranous. 



2. The ground-plate (Grundplatte) , the zone from which the 

 motor roots spring. 



3. The alar plate (Fluegelplatte) , the zone into which the sensory 

 roots enter. 



4. The intercalary plate {Schaltplatte) . 



5. The lateral plate (Seitenplatte) . 



6. The vertical plate {Scheitelplaite) . 



Numbers 1 and 6 are the median zones. They are more con- 

 stant both in the phylogenetic and the ontogenetic series than the lat- 

 eral zones. The median zones are normally membranous throughout 

 life. If they become massive at any point (cerebellum, optic lobes, 

 etc.) it is only through the influence of the lateral zones. That, how- 

 ever, the median zones have not utterly lost the power to differentiate 

 into ganglion and neuroglia cells is shown by the epiphysis and its 

 accessories (parietal eye). Probably the optic vesicles have evagi- 

 nated from the base-plate just as the epiphysis has from the vertical 



1 Zut Geschichte des " Cortex cerebri." Verh. d. Anat. Ges., 8 Versam., 

 Strassburg, May, 1894, pp. 193-198. 



2 Der Bauplan des Wirbelthiergehirns. Morphologischen Arbeiten, herausg. 

 von Dr. G. Schwalbe, Jena, IV, 2, pp. 131-150. 



