Muscles and Nerves 201 
realize what resource and intelligence they frequently 
display in adapting themselves to new untried con- 
ditions, a smooth brain does not seem such an inferior 
organ as is often inferred by writers on the subject. I 
would willingly match a crow against a walrus any day, 
in a test of intelligent behaviour! 
Between the hemispheres is a small projection which 
Fic. 146.—Vertical section through skull of bird, showing great size of brain. 
is called the pineal body. It is very tiny, and we know 
little of its function at present, but its history is one of 
the most interesting chapters in the evolution of the 
bird, which we shall leave to the chapter on the senses. 
The other most conspicuous part of the brain is the 
cerebellum, or “little brain,’ a section of which shows 
a most remarkable tree-like appearance. This has been 
called the arbor vite—the tree of life. 
It is in this portion of the brain that a few tiny drops 
