192 AVES (the bird) 



8. The Excretory Organs. Find two dark-colored organs, 

 the kidneys, close along the back. 



Trace a ureter from each to the cloaca. 



9. The Reproductive Organs, paired in the male and single 

 in the female, also open by ducts into the cloaca. 



10. The Nervous System. 



(1) The Brain. 



(a) Carefully cut away the upper part of the skull 



and expose the brain. 



(b) Is it smooth or convoluted? 



(c) Identify and describe the cerebrum, cerebellum, the 



two olfactory lobes in front of and below the cere- 

 brum, anterior to and below the cerebellum. 



(2) The Spinal Cord. 



(a) Remove the bone along the cervical vertebrae and 



expose the spinal cord until the brachial plexus is 

 reached. 



(b) Trace nerves to the wings. 



(c) Continue to expose the spinal cord until the lumbar 



plexus is reached. 



(d) Trace the nerves from the lumbar plexus to the 



thigh, 

 /e) Continue exposing the spinal cord till the sacral 

 plexus is reached. 



(f) Trace the sciatic nerves to the legs. 



(g) If possible, continue exposing the spinal cord until the 



plexus pudendus, which supplies the tail, is reached. 



(3) Sketch the brain and spinal cord, showing the princi- 



pal plexuses. State the use of each part of the 

 brain. Tell what part of the body is supplied with 

 nerves from each plexus. 



C. The Endoskeleton ^ 



Clean away the flesh from the bones of the unmutilated bird, 

 leaving all parts articulated. 



Weigh. What per cent, of the bird is bone? Why are the 

 bones so light? 



^See Fig. 216, " Principles of Economic Zoology." 



