150 Practical Zoology. 



the brain. Only the first and second pairs of cranial nerves 

 directly enter the cerebrum. 



3. Back of the optic nerves, near the middle line, is the third 

 pair of nerves. 



4. The fourth pair extend up on each side into the groove 

 between the cerebrum and the cerebellum. 



5. Back of these is the larger fifth pair. This pair supplies 

 part of the face, and sends branches to the teeth. It is the 

 nerve affected in neuralgia of the face. 



6. Back of and inside of the fifth pair is the sixth pair. 



7. The nerves of the seventh pair are larger, and are farther 

 back and outward. These are the facial nerves, and control the 

 muscles of the face and the facial expression. 



8. Close to the seventh are the eighth, or auditory nerves. 



9. The ninth, tenth, and eleventh arise close together, farther 

 back and well up on the sides of the spinal bulb. 



10. The ninth supplies the back of tongue and the pharynx, 

 and is called the glosso-pharyngeal nerve. 



1 1 . The tenth pair pass down out of the brain cavity, give 

 off branches to the pharynx and larynx, and are distributed to 

 the heart, lungs, and stomach. These are the vagus nerves. 



12. The last pair of cranial nerves, the twelfth, arise near the 

 middle line of the spinal bulb. This pair supply the muscles of 

 the tongue, and are called the hypoglossal nerves. 



Draw the brain as seen from below, showing all these nerves. 



Separate the cerebral hemispheres, and with a sharp knife 

 split the brain lengthwise in the middle line. Make a drawing 

 of the inner face of one half. Note the branched appearance, 

 the arbor vitae, of the cerebellum. Trace the cavities of the 

 brain. 



THE LEGS OF THE RABBIT. 



Most of the following structures may be made out from a 

 shin bone of a sheep, readily obtained from the butcher. 



i. After removing the skin from the legs, observe the muscles, 



