Kappers, Teleostean and Selachian Brain. 3 



On the other hand, Hollard defended the interpretations of 

 CuviER and Gottsche. So, comparing the lemniscus fibers 

 which came from the optic tectum with the corona radiata in the 

 fore-brain of man, he accordingly called the lobi inferiores, 

 corpora striata, thus consummating the earlier errors, which, 

 however, were surpassed by Miklucho-Maclay, who not only 

 doubted the homology of the fore-brain, but even considered the 

 cerebellum of fishes to be the homologue of the mid-brain of 

 higher vertebrates, considering a dorsal enlargement of the ob- 

 longata to be the cerebellum. 



Happily his opinion was only defended by Gegenbaur; 

 neither Huxley, Balfour nor Sanders in England, nor Wilder 

 in America, accepting this interpretation, which was also rejected 

 by ViAULT and Rohon, to whom we owe good descriptions of the 

 brain of the selachians. Now^, while Bellonci's work on the 

 course of the optic tracts and those by Ehlers and Cattie on the 

 pineal gland settled forever the identification of the mid-brain 

 roof, our knowledge of the fiber tracts was greatly enlarged by 

 Fritsch and Mayser, whose excellent works are even yet 

 studied by every one who investigates this subject. 



They, however, did not give a good explanation of the fore- 

 brain of fishes, which we owe to Rabl-Ruckhard. As already 

 stated, the great difficulty until now had been the solid structure 

 of the anterior lobes, in which no pallium could be distinguished 

 from a striatum. Although Stieda had already regarded the 

 median fissure between the anterior lobes as a ventriculus com- 

 munis whose lateral walls he found covered with ependyma, even 

 he did not find the dorsal covering of this ventricle, which was 

 discovered by Rabl-Ruckhard who applied the principle already 

 given by Reichert that a mere ependymal membrane can be the 

 pro-stadium of a thickened nervous wall; and he found that the 

 pallium of the teleosts is such a membrane which does not contain 

 nervous substances in these fishes but in other animals becomes 

 the center for important fiber tracts. 



This discovery of Rabl-Ruckhard gave rise to the question 

 whether the whole pallium is here represented by membrane as 

 Edinger and Johnston believe, or whether the basal lobes 

 themselves contain parts which in other animals are situated in 

 the mantle, as C. L. Herrick maintained. This author, although 

 granting that the pallium itself is only represented as an ependy- 



