164 



ANATOMY OF THE CENTRAL NEEVOUS SYSTEM. 



larity between the turtle-brain and the avian brain; and, on the other hand, 

 by the deTelopment of the skull, which is never without influence. 



In higher vertebrates with the great development of the mantle appear 

 the grooves, or sulci. Since tliey are particularly developed in the mam- 



0^ 





W '^ — -^ 



Fig. 112. — Schematic sagittal section of a mammalian brain. 



malian brain, they will be minutely described in a later chapter. The brains 

 of most reptiles possess only the Fovea limbica as boundary between two 

 different portions of the mantle. However, there is recognizable in the large 

 snakes and still better in turtles another shallow groove, which lies near the 



Fig. 113. — External view of the brain of the lizard: 

 (Enlarged four times.) 



Vannnis. 



upper edge of the mantle and extends for a shorter or longer distance parallel 

 to it. In birds this Fovea coUateralis is more clearly developed. It is not a 

 real sulcus such as traverse the mammalian brain. We have to do here with 

 a ventral and dorsal projection of the mantle, which is dependent upon the 



