18() MARVELS OF POXD-LIFE. 



sessing a "ruling brain," the sole representative of 

 the class Archencephala. The next class possesses 

 a brain of less complexity and development, but 

 still elaborately constructed, and is named Gyren- 

 cephala^ literally, "wind-about brains." In these 

 the cerebral hemispheres are actually and relatively 

 large, and exhibit deep convolutions. The highest 

 members of this class are the chimpanzees and 

 gorillas. Below them come the "smooth brains," 

 Lissencephala^ of which the sloth, is the highest 

 representative. Below this class we find the "loose 

 brains," Lyencephala^ in which the cerebral hemi- 

 spheres are loose, or comparatively disconnected. 

 Of this class the kangaroo may be taken as a 

 type. 



Considered with reference to the humble creatures 

 under our consideration, the classification of the mam- 

 malia may appear a somewhat foreign subject, but 

 the highly-organized beings belonging to that great 

 division enable us to perceive in the most striking 

 manner the important consequences that flow from 

 the possession of a brain developed so as to 

 minister to a life of extensive relation to external 

 objects, and having its various parts so bound 

 and tied together as to render possible a powerful 

 and combined action of the various faculties with 

 which its several portions are endowed. If we 

 should ever ari'ive at a satisfactory classification 



