136 LYMPHATIC SYSTEM. 



secrete the mucus which is spit up from the trachea; but I 

 have more than once distinctly filled them with mercury by 

 injecting the lymphatic vessels of the lungs, and therefore it 

 is evident that they are not mucous but lymphatic glands. 



The lymphatic vessels from the anterior part of the left lobe 

 of the lungs pass into the angle between the jugular and sub- 

 clavian vein of the same side, joining the thoracic duct at its 

 termination, whilst those from the fore part of the right lobe 

 do not communicate with the thoracic duct, but pass into the 

 angle between the right jugular and the right subclavian vein. 

 These lymphatics from the anterior parts of the lungs are pro- 

 bably accompanied by those of the heart, which are represented 

 by the accurate Nuck in his ' Adenographia, ' fig. XLI. 



The thoracic duct, after receiving the vessels before men- 

 tioned, passes behind the ascending aorta, see Plate III, and 

 goes to the left side, terminating in the angle between the 

 jugular and the subclavian vein. But, just before its termina- 

 tion, it generally goes higher up than the angle, and then 

 bends down towards it, as is seen, Plate III, b, c. Sometimes 

 there are two thoracic ducts instead of one, but this rarely 

 occurs in the human subject, but it is not unfrequent for the 

 duct to split near the upper part of the thorax, and the two 

 branches, after spreading out from one another, commonly 

 unite again at their termination in the angle between the left 

 jugular and subclavian veins. I never saw any part of the 

 thoracic duct terminate in the right subclavian of the human 

 body, though such a circumstance has been observed by others. 1 

 But I have now by me a preparation where the "duct splits at 

 the upper part of the thorax into two branches, one of which 

 enters the angle between the jugular and subclavian of the left 

 side, and the other opens into the left subclavian vein, about 

 half an inch on the outside of that angle. 



In the description of the lymphatic vessels which lie near 

 the spine, I have mentioned only a few glands, and in Plate II, 

 i,i, i where those vessels are exhibited no glands are represented. 

 This I at first considered as an imperfection in the preparation, 

 and had intended to make a drawing from another, but there 

 are two reasons which have induced me to lay the present one 

 before the reader. First, the lymphatic glands are not con- 

 1 Dr. Meckel, Epist. ad Hallerum, p. 30. 



