lt6 OBSERVATIONS ON THE GANNET. 



The clavicles, or what is commonly called the 

 merry-thought, which is usually affixed to the 

 point of the keel of the breast-bone by a ligament, 

 is, in the gannet, so firmly united, as to appear a 

 part of it. 



The very singular structure of this bird, so 

 widely different from any that had before come un- 

 der examination, could not surprise me more, than 

 the discovery of a new and singular insect found 

 to inhabit the cellular membrane attached to the 

 skin. It is well known, that the species of Vermes 

 intestinales, found to inhabit almost all the inter- 

 nal parts of animals possessed of a red circulating 

 fluid, are extremely numerous, and that many 

 others are not wholly destitute of them ; but no 

 instance, to my recollection, has been authentical- 

 ly proved, of a true insect having been observed, 

 constantly to inhabit and propagate in a similar 

 situation. A description and figure of this singu- 

 lar species of insect accompanies this paper. 



Those who have had an opportunity of examin- 

 ing a great variety of birds, will have noticed the 

 great difference in the general construction of the 

 body, and in particular the abdominal parts, of the 

 aquatic tribes; and doubtless will have observed 

 how much more capable they are of enlarging the 

 cavity of the body than land birds, and by that 

 means are enabled to contain a much larger sup- 

 ply of air, so essential to the vital principle under 



