GANNET. 
195 
From a repetition of these experiments upon several subjects, it be- 
came evident that there was a communication between the lungs and 
the cellular membrane that covers the greater part of the body, as well 
as with the whole cavity of the body, but that, by reason of some val- 
vular contrivance, the skin could not be artificially inflated through the 
lungs, although air would readily pass in a contrary direction. It is 
also clear that there is no direct communication between the sides. 
In order to examine this extraordinary structure, we made a longi- 
tudinal incision the whole length of the body, a little on one side of 
the keel, or what is commonly termed the breast-bone ; by this means 
the membrane that connects the skin to the body, and cuts off the 
communication between the sides, was easily examined; but nothing 
was observed, indicating that a communication could be effected, even 
at the will of the bird. On each side, nearly equidistant between 
this pectoral membrane and the back, is situated another longitudinal 
one, very similar to the last, but perforated; between this and the 
pectoral are about nine irregular transverse membraneous septa, that 
hold the skin firmly to the body, having a free communication with 
each other. The skin is also furnished with a transparent cellular 
membrane, the cells being regularly perforated close to the base of each 
feather. At the upper part of the breast is a large bag, which extends 
some way up the neck ; this is attached to the skin by the septa of 
innumerable small cells, but no opening into this cellular bag could be 
discovered ; the introduction, however, of a small pipe through an 
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 internal parts appeared to be under the shoulder-blades, (cla- 
vicles,^ 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 divaricates, 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 our researches, we observed at the bottom of each lobe of 
the lungs, a considerable opening for the passage of air into the cavity 
of the body. But what arrested our particular attention, was a won- 
derful provision of nature for the protection of the vital parts, by 
guarding the viscera with a strong integument, that preserves them in 
a proper degree of moisture, and contributes to the due secretions for 
lubricating those parts, so essential to the functions of their delicate 
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