CTGNUS FERUS. 319 



seated [cavity or sinus] just below the bottom of the orbit, which is 

 pretty large, and is very irregular on its outer surface: the inner 

 surface is the septum between the two eyes. This has a duct passing 

 forwards which opens into the cavity of the nose just behind the largest 

 turbinated cartilage. There is a third just above this opening, which is 

 less, situated before the bottom of the orbit, and opening under the 

 great turbinated cartilage l . 



The lacrymal gland, which is as large as in the human subject, is 

 placed at the bottom of the orbit, just above the second cavity and 

 behind the third. It sends a large duct forward and outward, with 

 the abductor muscle, which opens behind the membrana nictitans. 



The puncta lacrymalia are very large : they open into the sac, which 

 is an inch long ; and its duct, which is pretty large, opens into the nose 

 below and a little before the great turbinated cartilage. These carti- 

 lages are very vascular. 



The Wild Swan [Cygnus ferus, Briss.]. 



The only difference I could observe between this swan and the 

 common \_Cygnus olor~\, was a yellow part at the setting on of the beak. 

 It has a gizzard like a common swan, which contained some pulpy 

 vegetables and a tolerably fine sand, not bigger than pins' heads : the 

 thickest part of the horny lining was not above yjjth of an inch. This 

 bird may be said to have three mesenteries : one for the duodenum, the 

 second for the jejunum, and the third for what may be called the ileum. 



The duodenum makes a fold as usual in birds, on the first mesentery. 

 The jejunum makes three folds upon the second mesentery ; it passes 

 down upon this flat mesentery, folds up upon itself, turning over the 

 upper edge of that mesentery and passing down on the opposite side ; 

 it then turns up upon itself again, making a similar fold to the first ; 

 then turns round, encircling the whole ; and, when got to the upper 

 part, it leaves this mesentery, beginning to make folds upon the third 

 mesentery, on which, as ileum, the gut makes three folds. After passing 

 about 10 inches it folds up upon itself again, then makes another turn 

 down and up upon itself; from thence passes down between these two 

 folds, winds round the lower part of this common mesentery, going up 

 upon the posterior surface of it, and is attached to the two caeca. It 

 then makes a turn down towards the back and forms the rectum, at 

 the upper part of which arise the two caeca. The rectum terminates in 

 the anus, which has a very different surface from the gut, appearing to 

 be covered with a cuticle. 



The ductus cysticus and hepaticus enter the duodenum at the upper 



1 [Hunt. Prep. Phys. Series, Nos. 1536, 1537.] 



