94 PHYSIOLOGICAL SERIES. 



D. 92. The brain of a Bib (Gadu* luscus) exposed from the left 

 and ventral aspects. 



In comparison with the brain of the Cod, there are 

 noticeable differences in the relative proportions of the 

 j.arts the cerebral basal ganglia and optic lobes being 

 much more nearly equal in size. This is due partly to an 

 increase in the si/e of the basal ganglia, and partly 

 to a decrease in the optic lobes relative to the brain as a 

 whole. The right optic nerve crosses below the left. The 

 HU \a-culo-u- 5- more prominent than in the Cod, and 

 the pituitary body very much smaller. The lobi inferiores 

 mc.-t in the mid-line behind the saccus vasculosus. 



0. C. 1380 A 5. 



D. 93. The head of a Five-bearded Rockling (Motella mustela) 

 with the ventral surface of the brain exposed. The optic 



nerv-- CTO -the right below the left at a considerable 



distance in front of the brain. In this specimen parts of 

 the trigeminal nerve are also shown. 0. C. 1380 A 7. 



D. 94. The head of a Sole (Solea vulyaris) with the brain exposed. 

 Owing to the torsion of the skull the fore' part of the 

 lira in i- rotated to the right, but the region behind the 

 ojitie lobes is quite similar to that of other fishes except for 

 a hardly perceptible tendency to bend towards the right. 

 The medulla is fairly long, witb a pair of very prominent 

 lobe* (facial ?) upon its dorsal -urfaee. The cerebellum is 

 -mall, nearly globular in shape, and projects slightly back- 

 ward- over the rhomboid fossa. The optic lobes are al-o 

 of moderate dimen-ion-. and give oft' equal i/.ed optic 

 nervrs. Tin- left ncr\ e paaMi above the right and twists 

 round abo\e the -phcnoid l>one to reach the left eye which 



i-di-pl;iced to the right side of the fish. 



The thalamencephalon is remarkably elongated for a 

 Te|eo-te;m, and form- a conspicuous neck between the 

 optic lobe- ;ind corpora Mriata. 



The olfactory bulbs an- large and are separated from the 

 basal ganglia by a considerable constriction. The parts 



