NERVOUS SYSTEM. VERTEBRATA. 97 



The brain is feebly developed and occupies only a small 

 part of the spacious cranial cavity. The fore-brain is re- 

 markably small ; it forms a pyramidal eminence in front of 

 the optic lobes. The bulbi olfactorii are sessile on the 

 basal ganglia, but in this specimen are hardly to be distin- 

 guished. They give off delicate olfactory nerves. The optic 

 lobes are large in comparison with the feeble development 

 of the rest of the brain, but are not in reality particularly 

 strong. They are separated in the mid-dorsal line by a 

 shallow groove. The cerebellum is extremely small for a 

 Teleostean, forming merely a little rounded excrescence 

 between the hinder margins of the optic lobes. The 

 medulla is followed by a swollen region of the cord with 

 a single pair of eminences upon its dorsal surface. This 

 enlargement is by some included in the medulla, and 

 homologized with the vagal lobes, but from its micro- 

 scopic character (Ussow, Arch. Biol. t. iii. p. 642) it 

 seems that it more likely is a modified part of the cord, 

 comparable to the metameric swellings found in this region 

 in the Gurnard. It should be noticed that in both cases 

 the anterior spinal nerves are strongly developed. 



The pituitary body is a remarkable structure both for 

 its enormous size and its position a centimetre or more 

 in front of the brain. It is spherical and connected to the 

 infundibulum by a long delicate pedicle. The pineal 

 gland is situated in a similar way beneath the cranial roof 

 far in front of its point of origin upon the roof of the 

 thalamencephalon. The same forward shifting is noticeable 

 to a less degree in the eyes, in the position of the optic 

 chiasma, and in the point of exit from the brain of the 

 trigeminal complex of nerves. Possibly in all cases it is 

 due to the great development of the anterior face-region. 

 The lobi inferiores are peculiarly small ; they lie one on 

 either side of a prominent saccus vasculosus. 



In this specimen the spinal cord is v also shown (for 

 description see D. 754). 0. C. 1308 N. 



D. 101. The isolated brain of a Fishing-Frog (Lophius pisca- 

 torius). This specimen shows the features mentioned in 



VOL. n. H 



