Muscles and Nerves 



20I 



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 an}^ day, 

 in a test of mtelligent behaviour! 



Between the hemispheres is a small projection which 



Fig. 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 vitcp — the tree of life. 



It is in this portion of the brain that a few tiny drops 



