DISTRIBUTION OF THE LYMPHATICS. 175 



in the thoracic duct. The pulmonary lymphatics, very numer- 

 ous, are distinguished into superficial and deep-seated. The 

 first take their rise from the surface of the lungs, creep along 

 under their enveloping membrane, and make for one or more 

 of the bronchial glands. The deep set, which originate from 

 the air-cells, and from the parenchymatous tissue, follow the 

 divisions of the pulmonary veins, run to the roots of the 

 bronchiae ; there unite with the superficial, and perforate one 

 or two of the bronchial glands. 



" The cardiac lymphatics derive their origin either from the 

 surfaces (both exterior and interior) of the heart, or from the 

 muscular substance of the organ j they mount upon the cur- 

 vature of the posterior aorta, and disappear in the cardiac 

 glands. 



" The lymyhatics of the superior part of the mediastinum, 

 and of the oesophagus, join, some the intercostal, and others 

 the bronchial ; those coming from the anterior part of this 

 membranous partition, from the thymus, trachea, and oesopha- 

 gus, unite, either with the pectoral, or close with the cardiac 

 and anterior intercostal. 



" 3. LYMPHATICS OF THE HEAD. 



" The lymphatics of the head form two planes, a super- 

 ficial and a deep one. The superficial pursue the course 

 of the cutaneous veins, and run in part to the sublingual and 

 glutteral glands. The deep vessels, which come from the 

 nostrils, fauces, palate, &c, also run to the glutteral and sub- 

 lingual, in which they unite with the superficial. From 

 these two groups of glands, through which pass the lym- 

 phatics of the head, depart several large branches, two or 

 three of which descend upon the anterior face of the trachea ; 

 others follow the course of the deep-seated and cutaneous 

 veins, unite with those of the neck, and descend to the front 

 of the chest. Almost all these vessels terminate in the 

 thoracic duct ; some few alone, on the right side, ending in 

 the right axillary trunk. 



