258 Mr. Macartney’s Account of an Appendix 
the arrangement of the internal coat of the intestine, the ap- 
pendix is constantly found to present a surface composed of 
small cells, similar to those assemblages of mucous follicles 
that are met with in different parts of the alimentary canal. I 
have not observed in any instance, that the appendix received 
the natural contents of the adjoining intestine, but have always 
found it filled with a mucous fluid, I therefore conclude that 
it performs the office of a mucous gland. 
The magnitude and form of the appendix are not so deter- 
mined as its structure. In the snipe, as already mentioned, it 
exceeds in length the coeca of the great intestines ; its width 
also is equal to that portion of the gut, from which it arises ; 
but it becomes smaller towards the extremity. 
In the curlew I have found it of a very considerable size, 
although less in proportion to the intestine than in the snipe. 
It is wider in the middle than at its origin or termination. 
In the woodcock it is nearly as capacious as in the curlew. 
I have found it very slender, but above an inch long, in the 
black coot. In this bird the intestines are all long and slender, 
and the coeca of the great intestines singularly so. 
The appendix in the swan and goose is rather larger than 
in birds generally, and ends in a point. 
It is remarkably small in the heron. 
In a great number of the passerine and gallinaceous birds 
that I have examined for the purpose, I have found it very 
small. 
It is short also in the hawk. 
The greater size which this process of the intestine pre- 
serves in the snipe, curlew, and woodcock, would seem to 
depend upon the mode of feeding and habits of those birds ; 
