108 NTRODUCTION TO ZOOLOGY. 



left subclavian. Find also the right subclavian and 

 the right carotid. Trace the aorta backward, where 

 it is called the dorsal aorta. 



4. Find veins leading the blood to the heart. The 

 one from the liver is the vena cava inferior. Find 

 two others coming from the front, right and left venae 

 cavee superiores. 



5. Find the artery which carries the blood to the 

 lungs. This is the pulmonary artery. Find veins 

 which carry the blood back from the lungs. These 

 are pulmonary veins. How many are there? 



6. Cut off all the arteries and veins as far from the 

 heart as you can. Identify the parts of the heart. 



7. Find the two auricles, right and left. What 

 tube enters each auricle? 



8. Identify the two ventricles, right and left. 

 What arteries leave each ventricle? 



9. Make a complete drawing of the heart and 

 blood vessels. 



The Reproductive Organs. 



1. In the back, find the ovaries in the female, or 

 two white oval bodies, the testes, in the male. 



2. Find a tube leading from the reproductive 

 organs to the cloaca. In the female, this is called the 

 oviduct. 



3. In the posterior part of the back, find the kid- 

 neys, two dark colored, irregular bodies. Find tubes 

 leading from the kidneys to the cloaca. 



The Respiratory Organs. 



1. Find the trachea, or windpipe. Describe its 

 structure. How many rings of cartilage has it? 



2. Find the larynx, at the top of the trachea. 



3. Find the two bronchial tubes, at the bottom of 

 the trachea. 



