250 THE BIOLOGY OF THE ANIMAL 



pituitary body or hypophysis. What is the 

 shape of the latter ? Color ? Size as compared 

 with the tuber ? 

 Draw the ventral aspect of the brain. 



Examine another brain which has been hard- 

 ened and removed from the skull, and note the 

 various parts as seen from the side. Draw the 

 lateral view of such a preparation. Make verti- 

 cal sections, both transversely and longitudinally- 

 through a brain and study the sections in order. 

 Draw. 

 h. The spinal cord. — Study carefully the shape of 

 the spinal cord as seen from above. Notice the 

 enlargements, brachial and lumbar, at the 

 points where the nerves for the limbs originate. 

 Note that the posterior end of the cord tapers 

 into the filura terminale, which extends into the 

 canal of the urostyle. Does the cord fill the neu- 

 ral canal ? Note this particularly with reference 

 to the posterior portion of the neural canal where 

 the end of the cord, together with the roots of 

 some of the nerves which run to the hinder parts 

 of the body, forms the cauda equina. Look for 

 the dorsal fissure, which extends along the 

 cord. How far can you trace it? Examine a 

 cord which has been removed from the spinal 

 canal. Can you find a ventral fissure? Do these 

 correspond to parts seen on the brain ? Examine 

 a transverse section of a cord and find the cen- 

 tral canal. To what does this correspond in 

 the brain? Note also the roots of the spinal 

 nerves. 

 Make the drawings necessary to show the structure 

 of the spinal cord. 



