266 THE BRAIN OF QUADRUPEDS AND 



of the brain of the Kangaroo (fig. 68), together with 

 those of the Hare and the Squirrel (figs. 76, 82). In 

 these animals they leave the ' olfactory lobes ' more or 

 less uncovered in front, and sometimes the ' corpora 

 quadrigemina ' in the same condition behind. But in 

 Kuminants, Solipedes and Carnivores (figs. 94, 72, 87) the 

 Cerebral Lobes increase in size, so as not only to cover 

 the before-named bodies in front and 

 behind, but also in part to overlap the 

 Cerebellum. 



In the Seal, the Porpoise and the 

 Dolphin (figs. 77, 101), the Cerebral 

 Hemispheres undergo a still more 

 marked increase in size. In these ani- 

 mals, also, as well as in Quadrumana 

 and Man, we no longer find a distinct 

 'pyriform process/ recognizable as a 

 part of each ' temporal lobe ' at its 

 FIG. si.-Brain of the under and inner surface such as exists 



Squirrel, Hemispheres sepa- ., .. ,, ., , f 



rated so as to expose the m the majority of the lower forms of 



great basal ganglia. (Solly.) Q ua drupeds. 



B, Cerebral hemisphere; *, n -,- t,- i, i, i t, 



cerebellum ;M, corpus stria- These bodies, which have also been 



. C ' D> named ' hippocampal lobes,' are merely 

 the lowest portions of the Temporal 

 Lobes more or less separated from the remainder by a 

 superficial depression. The continuity existing between 

 the Olfactory Peduncles and these parts of the brain is 

 particularly well marked in the Red Coatimondi, the 

 Agouti, the Porcupine and the Water Rat, as may be seen 

 from the figures given by Tiedemann. This connection 

 is also indicated by our figs. 69, 73, 82, 93 and 94. 



These ' pyriform processes ' are hollowed by spurs of 

 the lateral ventricles. In the animals in which they are 

 well marked, the Olfactory Peduncles and Lobes are like- 



