10 Mr. Burton on the Natural History and Anatomy 



greater length than breadth ; they run down through the whole 

 cavity on each side of the spine. The gall-bladder is attached 

 to the inferior surface of the right lobe, is very large, and in the 

 birds dissected was found full of bile, in colour and consistence 

 exactly resembling that found in the human gall-bladder. 



The oesophagus, as in all these birds, is extremely capacious, 

 and very little inferior to the stomach in its dimensions ; a struc- 

 ture well adapted to the precarious mode of feeding to which 

 they are subject, as they are sometimes for a long time desti- 

 tute of food, and at others gorge to such a degree as to fill not 

 only the stomach, but the oesophagus and even the mouth with 

 entire fish, which are left there to be digested at leisure. I have 

 seen one of the Sulce, when taken, so full of flying-fish as to be 

 unable to close its beak. The parietes of the oesophagus are 

 nearly half an inch in thickness, and the longitudinal bands of 

 muscular fibres are very large and distinct through the whole 

 canal. The convolutions of the intestines are not numerous, 

 and soon terminate in the cloacae. 



The volume of the brain, as has before been remarked, is par- 

 ticularly small, considering the largeness of the head and body : 

 indeed the same remark will hold good with regard to the gene- 

 rality of sea-birds. 



The sac situated under the throat of the male is composed of a 

 thin carunculous membrane, highly vascular, and in structure 

 precisely similar to the gills of the common cock : when flaccid 

 it is thrown up into rugae, but when distended it is smooth, and 

 the appearance of follicles is lost. On the inside of this sac is 

 placed a thin muscle, which, arising in the lower part of it, 

 forms a loose expansion towards the centre, and sending off se- 

 veral small tendinous chords, is attached by them to different 

 parts of the superior parietes of the sac, exactly in the same 

 manner as the chorda tendinece are attached in the ventricles of 



the 



