ANGIOLOGY 255 



along the side of the abdominal aorta, reaching a point anterior 

 to the celiaca. By receiving many vessels in this region it forms a 

 plexus around the aorta, and finally divides into two vessels, the 

 right and the left, ducti thoracici. 



The lymph vessels of the left side of the head, the neck, and the 

 lung, and the left wing, and also lymph vessels of the proventriculus 

 and the throat enter into the left ductus thoracicus. They accom- 

 pany the jugular vein and are closely associated with the thyroid 

 gland. 



The right thoracic duct receives the lymph veins from the right 

 cervical lymph vein, and the right side of the head, the neck, the 

 lung, and from the right wing. 



After the right cervical lymph vein has passed through the right 

 thyroid gland, it divides into two branches, one branch emptying 

 into the right thoracic duct and the other into the vena cava dextra. 



The lymph vessels of the liver, the stomach, the pancreas, and 

 the duodenum enter near the root of the arteria celiaca into the 

 large lymph trunk. The lymph vessels of the remainder of the 

 intestines, of the kidney, and of the generative organs empty farther 

 caudally. 



The lymph vessels of the intestines take up the emulsified fat. 

 This emulsion in birds is colorless. The vessels pass upward along 

 the mesenteric arteries. There are no mesenteric glands. These 

 vessels form a plexus around the arteria celiaca. The lymph vessels 

 of the posterior extremities accompany the artery, especially the 

 anterior iliaca externa, and empty into the thoracic duct at the 

 point of the anterior iliaco-communis. 



The lymph vessels in birds are numerous. The lymph glands are 

 few. They are only visibly found in the anterior breast and the neck 

 region, and sometimes in the wings. Lymph follicles are numerous 

 in the intestines. 



The thin walls of the lacteals, of the lymph vessels, and of the 

 thoracic duct are made up of two tunics, the inner being the thinner 

 and weaker. 



The lymphatics of the foot unite to form the vessels along the sides 

 of each toe. In palmipedes there are anastomosing branches which 

 pass from the lateral vessels of one toe to those of the adjoining toe, 

 forming arches in the uniting web of the foot. These branches form 

 a small plexus at the anterior part of the digito-metatarsal joint, 

 from which pass three or four lymph vessels. The anterior and 



