OBSERVATIONS ON THE GANNET. 183 



cells, but no opening into this cellular bag could 

 be discovered ; the introduction, however, of a 

 small pipe through the artificial aperture, clearly- 

 demonstrated a passage to the lungs, as the whole 

 internal cavity of the body was inflated, and the 

 air issued from the trachea. Upon opening this 

 bag, the passage of communication with the inter- 

 nal parts appeared to be under the clavicles, as a 

 thin perforated membrane was perceived at the 

 bottom, leading to the thorax, not directly into 

 the lungs, but near the part where the trachea di- 

 varicates, and afterwards communicating with the 

 lungs. It could not, however, be discovered 

 where the air could find a passage from the great 

 magazine into the cellular bag, and yet there is 

 every reason to conclude that at this part some 

 valvular passage exists. 



Pursuing my researches, I observed, at the bot- 

 tom of each lobe of the lungs, a considerable open- 

 ing, for the passage of air into the cavity of the 

 body ; but what arrested my particular attention, 

 was a wonderful provision of nature, for the pro- 

 tection of the vital parts, by guarding the whole 

 viscera with a strong integument, that preserves 

 them in a proper degree of moisture, and contri- 

 butes to the due secretions for lubricating those 

 parts, so essential to the functions of their delicate 

 nature, which might otherwise be too quickly car- 

 ried off, by the constant circulation of fresh air 

 that nearly surrounds them ; for this integument 

 is held only by ligaments to the back and front, 



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