408 



DR. J. MURIE ON THE EMU. 



[Apr. 11, 



wliich I have had drawn from nature, it will be seen, however, that 

 in the undistended condition of the pouch the margins of the tracheal 

 opening are not widely separated, the trachea itself being more or 

 less uniform in calibre, while the walls of the sac are rather cylin- 

 drical than otherwise. 



Fi£ 





Lower portion of the neck of the adult ? Emu seen in front, displaying tlie 

 tracheal ponch {T.j). T.p'.) opened and dragged back on either side by 

 hooks. The feathers are cut short at the tips. ap. Aperture or deficiency in 

 the tracheal rings, c. d. s. Cid de sac of left u])per end. /. h. f. b' . Fibrous 

 bands which drag outwards the tracheal cartilages during inflation of the sac. 



Dr. Knox has compared the size of the sac to that of a man's 

 head ; I have found it in the adult female to have the following di- 

 mensions when laid open : — Greatest length, taken upon the left side 

 of the trachea, 14^ inches; but over the trachea itself it measured 

 only 1 1 inches. A little pouch or cul de sac (fig. 1, c. d. s.) reached 

 upwards on the left side of the trachea for above 3 inches, giving 

 the increased length at this part. This sacculus appears to corre- 

 spond with a similar dilatation observable in Knox's figure. The 



