Kappers, Teleostean and Selachian Brain. 6l 



I think a good one, though it is surely better to keep the name 

 already known to every one who has studied the acoustic connec- 

 tions — fasc. longitudinalis lateralis. 



I have next to mention the tr. loho-cerebeJlaris w^hich merely 

 passes through the mid-brain and whose origin was described in 

 the second chapter when treating of the hypothalamus. It is 

 evident that this tract is the homologue in the fishes of the tr. 

 tegmeitto-cerehellaris of the higher animals. 



In agreement with C. L. Herrick, whose opinion I am more 

 and more inclined to accept, we are to believe that the posterior 

 region of the lobi inferiores is the homologue of nuclei of the teg- 

 mentum of the higher vertebrates. With the disappearance of the 

 lobi inferiores this region would have come into the basis mesen- 

 cephali. In view of this fact I consider it not impossible that 

 C. L. Herrick is correct in considering the recessi inferiores of 

 these lobes as the homologue of the corpora mammillaria. 

 Edinger, who in both the selachians and the teleosts places the 

 tegmentum in the hypothalamus, describes the tr. tegmento- 

 cerebellaris as "exceedingly constant." In Gadus it consists of 

 very important bundles, almost all medullated, and decussating 

 behind the exit of the oculomotonus after which they enter the 

 cerebellum. 



I could find no more mid-brain tracts forming connections 

 between the hypothalamus and the cerebellum, though more have 

 been described by other authors. Thus, Goldstein describes 

 behind the nucleus rotundus a nucleus ruber from which a tract 

 runs through the mid-brain into the cerebellum, just as has been 

 described by Catois. The latter author, however, seems not 

 to be quite convinced of this fact. Goldstein described still 

 another connection of his nucleus ventralis (nucleus rotundus of 

 other authors) and the cerebellum which I could not find, nor the 

 medullated connection of the same nucleus mentioned by Herrick. 



Two other mid-brain tracts, however, must be mentioned here. 

 They are the fasciculus retroflexus and the tractus loho-peduncu- 

 laris, both described in the second chapter as ending in the corpus 

 inter pedunculare, the first after crossing, the second uncrossed, 

 the first originating from the ganglia habenulae and the second 

 from the medial posterior part of the lobi inferiores. Their 

 origin and course have been described in the second chapter. 

 Fig. 5 (Plate XII) gives a good idea of their ending. 



