THE RESPIRATORY SYSTEM. 159 
Fic. 83. PuHotocrapH oF A Lunc Corrosion oF A Puma IN MorpHo- 
Locic Museum oF Princeton University. The specimen was pre- 
pared by Mr. Sylvester. The trachea with all its ramifications was 
injected with white paraffin, and the pulmonary artery with red 
paraffin, after which the lung substance was eaten away with acid. 
tr, Trachea; br, bronchus; b, bronchial tube; c, bronchiole. The pul- 
monary artery and its branches are much darker than the air tubes. 
