EXPLANATION OF PLATE 2. 



Fig. 1. The thorax and abdomen of an Ostrich, opened to show the great 

 air cells which communicate directly with the lungs, and transmit the air 

 to different parts of the body, t, the trachea or wind-pipe 6, the bronchia 

 pp, the lungs, the greater part of which are concealed by the great air 

 cells c, c, c, c, air cells at the bottom of which may be perceived the open, 

 ings of the bronchiae e, other cells, which communicate with the preceding 

 co, the hearl g t the gizzard t, the intestines. 



Fig. 2. The inferior larynx of a singing bird f, the trachea 6r, the 

 bronchiae 2, the inferior larynx m, muscles of the vocal apparatus. 



Fig. 3. The tongue and trachea of a bird Z, the tongue i, the cornu 

 of the os hyoYdes Ztf, the superior larynx (r, the trachea , the glottis. 



Fig. 4. The digestive apparatus of a pigeon a, the oasophagus j, the 

 ingluvies or crop, o, the proventruulus or bulbus glandulosus (Seepage 21.) 

 g,the gizzard t, the small intestine i^, the large intestine /, the liver- 

 pa, the pancreas o, the ovary 00, the oviduct r, the kidneys cu, canal 

 of the ureter cl t the cloaca. 



