108 



SdiueAvluil Lackwaids iulo the liollow infuudibiiluni. If 

 this be now traced posteriorly, it is found tiist of all to 

 coinnuuiicate Avith the cavity of the pituitary body. 

 Almost at the same time, l)ut more dorsally, it is pro- 

 h)iig'ed on each side into the large cavities of the lobi 

 inferiores, whilst finally it communicates with the cavity 

 of the fine stalk of the saccns A^asculosus. The third 

 ventricle therefore is continuous with the cavities of the 

 pituitary body, lobi inferiores and saccus vasculosus. The 

 infundibulum of the Plaice is difficult to delimit, as it is 

 largely merged into the floor of the thalamus. Inciden- 

 tally we may draw attention in the latter to the \eij large 

 paired nucleus rotundiis, which is very striking in sec- 

 tions. Anteriorly the third ventricle passes into the large 

 median ventricle of the fore-brain (prosocoele), roofed over 

 l)y the pallium. The prosocoele is not prolonged into the 

 l)ulbi olfactorii as a ihinocoele, the bulbs being solid. 



Cunningham makes two assertions on the brain of the 

 Sole that appear to us to require confirmation. One is 

 that llie " position of the brain is almost entirely 

 iiiialfected by the change which has taken place in the 

 normal position of the fish," and the other is that " the left 

 olfactory lobe is somewhat larger than the right, a diit'er- 

 ence which is related to the great development of the left 

 olfactor}^ capsule." On the other hand, Malme states of 



the Sole {op. cit., p, o4) that " insbesondere 



ist der rechte Lobus [striatum] (derjenige der Augenseite) 

 viel grosser als der linke," and again that in Pleuronectids 

 generally " der Bulbus der Augenseite ist stets der 

 grosste." Malme's observations agree with ours on lh(^ 

 I'laice. Again, Cu)\ningham apparently overlooks the 

 work of Rabl-lliickhard on the brain of Teleosts, and 

 describes what are really the corpora striata as receiving 

 prolongations from the third ventricle. 



