262 



THE BRAIN OF QUADRUPEDS AND 



Where the Pons is well developed, the ' cerebral pedun- 

 cles,' being more covered, appear to be curtailed in 

 length (fig. 74, i, i). 



The Cerebellum in Marsupials (fig. 68), still consists 

 principally of the ' median lobe,' the surface of which is 

 marked by deep transverse fissures, giving rise to a series 

 of nearly parallel convolutions. Its ' lateral lobes ' exist 



Pig. 74.— Brain of Dolphin, under surface. (Owen, after Tiedemann.) a. Spinal 

 cord ; b, anterior pyramids ; c, Pons Varolii ; e, posterior inferior lobe of Ctrobolluni; 

 f, anterior inferior lobe, g, amygdaloid lobe, and //, flocculus, all lobes of Cerebellum. 

 i, ?, Cerebal ])eduncles; p, corpus albicans; o, pituitary boviy ; m, temporal lobe, 

 and /, anterior lobo of Cerebrum. Olfactory bulbs absent ; 2. optic nerves ; 3, motor 

 nerves of eyes (fourth nerve apj^ears from above the Cereliellum, in front of ;/) ; 

 5, the trigeminus ; 6, the sixth nerve ; 7, the facial, and 8, the auditory nerves ; 

 9,'glosso-pharyngeal ; 10, vagus ; 11, spinal accessory; 12, hypoglossal; 13, first cervical 

 nerve. 



merely as small appendages, and are tliought by some 

 anatomists to correspond in higher forms with certain 

 accessory lobules, named ' flocculi.' Among Rodentia the 

 lateral lobes show a marked increase in size, which is 

 obvious in the Hare (fig. 76), and still more so in the 

 Beaver (fig. 71) where these parts arc distinctly larger 



