132 Practical Zoology. 



color of the lungs when inflated with the color when collapsed. 

 Notice the subdivisions, or lobes, of the lungs. 



2. In another rabbit, later, open the abdominal cavity without 

 injuring the thorax. Pull back the liver, and the pink lungs 

 will show through the thin central part of the diaphragm. Keeping 

 the eye fixed on the lung, prick a hole through the diaphragm 

 near one side, and note the collapse of the lung. Is the lung of 

 the other side affected by this operation ? Open the chest and 

 note the thin partition separating the two sides of the chest. 

 This partition, the mediastinum, is a double membrane, and the 

 heart lies between its two layers. The following study of the 

 heart and lungs may be made with the heart and lungs of 

 the rabbit ; but if the same organs of a pig, sheep, or calf can be 

 obtained, it will be better to use them on account of their 

 greater size. 



Topics for Reports. The Fur-bearing Animals, such as the 

 Beaver, Otter, Sable, Mink, Muskrat, etc., with Accounts of their 

 Homes, Habits, and the Modes of trapping them. The Hudson 

 Bay Company. The Native Ruminants of North America, such 

 as the Musk Ox, Caribou, Moose, Elk, Deer, Sheep, Goats, and 

 Antelope. The Kinds of Bears native to North America. The 

 Mountain Lion. The Coyote. The Timber Wolf. The Wild 

 Cats. Prairie Dogs. The Weasel. The Badger. Jack Rab- 

 bits. Porcupines. The Buffalo. 



Read American Natural History, Hornaday. 



