THE BRAIN 109 



into two hemispheres, right and left. The cerebrum 

 is united below with the spinal cord by means of an 

 intermediate link which is conveniently referred to 

 as the brain-stem. Several subdivisions can be recog- 

 nized in the brain-stem and mention may be made of 

 the one which is next the cord. This is the medulla. 

 Ajb the back of the cerebrum and overhung by it is 



FIG. 29. The brain cut lengthwise in the mid-plane; in other words, 

 the right half seen from the left. Again the cerebrum is the chief 

 mass; the arched structure (c.c.) is the chief bond between the hemi- 

 spheres. The cerebellum presents a leaf-like pattern. Cavities can 

 be traced in the brain-stem. 



a rather large division of the brain known as the cere- 

 bellum. Its surface is marked by numerous fine corru- 

 gations. The cerebellum is furnished with abundant 

 connections with the brain-stem and so, less directly, 

 with the cerebrum above and the cord below. The 

 general ordering of the parts of the brain is best ap- 

 preciated from a diagram of a median section, or, better 

 still, from a model which can be parted in this plane. 



