2o6 VERTEBRATES 



(g) Make a tabulated list of the blood vessels on the left 

 side and those on the right side of the heart. Tabulate 

 the similarities and differences between the veins and ar- 

 teries. How does the blood reach the arteries from the 

 veins ? 



(h) Cut the veins and arteries as far from the heart as 

 you can and remove the heart with the delicate pericardium 

 that surrounds it. What blood vessels can you trace from 

 and into the heart? Make a drawing from the ventral 

 side showing all the tubes at the top of the auricles. Make 

 a diagrammatic drawing of the entire circulatory system. 



(i) Dissect the heart as in the pigeon. (See page 185.) 

 Find all the valves. Make out their uses. Draw interior 

 view (X4)- 



(10) The Respiratory System. — (a) Above the 

 lungs notice the trachea. Remove carefully the enveloping 

 membrane, exposing the trachea from the lungs to the 

 mouth. Are there muscles connected with it? What is 

 its position with reference to the esophagus? Is it open 

 or collapsed? Why? Trace the trachea down to the lungs, 

 and note its divisions into the right and left bronchi. Do 

 these tubes further divide? How many lobes to the lungs? 

 Lift the lungs and sever them and the trachael tube from 

 the esophagus, being careful not to cut the lung tissue. 

 Study the muscles at the top of the trachea which sur- 

 round the larynx. Remove the lungs and the trachea, being 

 careful not to injure the bone at the base of the tongue. 

 Spread out the lobes of the lungs and make a diagram of 

 the ventral view. 



(b) With a blowpipe inflate the kmgs through the 

 larynx. Note the amount of expansion. 



