108 
somewhat backwards into the hollow infundibulum. If 
this be now traced posteriorly, it is found first of all to 
communicate with the cavity of the pituitary body. 
Almost at the same time, but more dorsally, it is pro- 
longed on each side into the large cavities of the lobi_ 
inferiores, whilst finally it communicates with the cavity 
of the fine stalk of the saccus vasculosus. 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 lattér to the very large 
paired nucleus rotundus, which is very striking in sec- 
tions. Anteriorly the third ventricle passes into the large 
median ventricle of the fore-brain (prosocoele), roofed over 
by the pallium. The prosocoele is not prolonged into the 
bulbi olfactorii as a rhinocoele, the bulbs being solid. 
Cunningham makes two assertions on the brain of the 
Sole that appear to us to require confirmation. One is 
that the “position of the brain is almost entirely 
unaffected 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 differ- 
ence which is related to the great development of the left 
olfactory capsule.” On the other hand, Malme states of 
the Sole (op. cit., p. 34) that “imsbesondere . . 2 Saas 
ist der rechte Lobus [striatum ] (derjenige der Augenseite) 
viel grésser als der linke,” and again that in Pleuronectids 
generally ‘‘der Bulbus der Augenseite ist stets der 
grésste.” Malme’s observations agree with ours on the 
Plaice. Again, Cunningham apparently overlooks the 
work of Rabl-Riickhard on the brain of Teleosts, and 
describes what are really the corpora striata as receiving 
prolongations from the third ventricle. 
