CHAPTER IV. 



A DESCRIPTION OF THE LYMPHATIC SYSTEM IN BIRDS. 1 



THIS system consists in birds, as it does in the human sub- 

 ject, of three parts, viz. the lacteals, the lymphatic vessels, and 

 their common trunk the thoracic duct. 



The lacteals indeed, in the strictest sense, are, in birds, the 

 lymphatics of the intestines (see Note LIX), and like the other 

 lymphatics carry only a transparent lymph. And instead of one 

 thoracic duct there are two which go to the two jugular veins. 

 In these circumstances it would seem, that birds differ from the 

 human subject, so far at least as I may judge from the dissec- 

 tion of a goose, which was the bird I chose as most proper for 

 this inquiry, and from which I took the following descrip- 

 tion, after previously injecting its lymphatic system with quick- 

 silver. 



The lacteals run from the intestines upon the mesenteric 

 vessels. Those of the duodenum pass by the side of the pan- 

 creas, and probably receive its lymphatics : afterwards they get 

 upon the cceliac artery, of which the superior mesenteric is a 

 branch. Whilst they are upon this artery they are joined by 

 the lymphatics from the liver; here they form a plexus, which 

 surrounds the cceliac artery ; at this part they receive a lym- 

 phatic from the gizzard ; and a little farther, another from the 

 lower or glandular part of the oesophagus. Having now got to 

 the root of the coeliac artery, they are joined by the lymphatics 

 from the renal glands, or renal capsules; and near the 

 same part, by the lacteals from the other small intestines, 

 which vessels accompany the lower mesenteric artery. These 

 last-mentioned lacteals, before they join those from the duode- 

 num, receive from the rectum a lymphatic which runs with 



1 This description has already been printed in the Philosophical Transactions, vol. 

 Iviii, where I have added a plate, which was thought unnecessary in this hook. 



