448 PHILOSOPHICAL TRANSACTIONS. [aNNO 1720. 



I know Pecquet has given a figure of the thoracic duct in a dog, which is 

 double from the receptacle and is inserted by four branches into each axillary 

 vein. I believe with Bartholine, Barth. p. 6l6, 620, who has borrowed this 

 figure from Pecquet, that such an insertion is a lusus naturae. For though the 

 thoracic duct may be double, and is sometimes divided into two parts near the 

 subclavian veins, yet generally it is single, the lympha from all parts on both 

 sides the body being carried by proper lymphaeducts into one common thoracic 

 duct, that conveys this liquor, together with the chyle from the lacteals, into 

 the left subclavian vein, by one, three, or more branches. For there is as 

 great a variety in the number of these branches as in the places of their 

 insertion. 



Mr. Cowper injected the thoracic duct in a human being, and gave a figure 

 of that preparation in his book of Anatomy. But this figure is imperfect, and 

 the insertion of the thoracic duct so ill drawn, that little can be learned by it. 

 However, no anatomist has given any figure that shows the insertions of the 

 lymphatics from both arms and both sides of the head, &c. above the subcla- 

 vian veins, which appear so plain in the following figures. 



Fig. U, pi. 12, represents the passages or vessels, by which the chyle and 

 lymph pass into the veins of a dog; 12, 12, are the lymphatics that bring lymph 

 from the thighs and lower parts; 13, 13, lateral lymphatics arising from the 

 groin, testicles, and neighbouring parts; 14, the receptacle of the chyle; 15, 

 an indenture in the receptacle, through which passes one tendon of the dia- 

 phragm; l6, lymphatics from a neighbouring gland; 17 some lymphatics from 

 the diaphragm ; 18, an artery that serves the loins, and runs through a division 

 of the receptacle; 19, the pancreas Asellii; 20, the vasa lactea 2di generis ; 21, 

 the beginning of the ductus thoracicus; 22, some divarications of the ductus; 

 33, the continuation of the duct, and its progress; 24, the aorta descendens. 

 N. B. The arteries at 18 and 24, by their pulsation, and the tendon at 15, 

 much promote the ascent of the chyle and lymph. 



Fig. 12, at 25, represents a common divarication of the duct; 26, a lym- 

 phatic from some neighbouring gland; 27, a double lymphatic from the 

 secondary gland 42 in fig. 13; 28, that part of the thoracic duct, where both 

 its branches, and the lymphatics from the left side of the head and left fore-leg 

 meet; 29, the lymphatics from the left side of the head and left fore leg united, 

 they lie on the inside of the vein ; 30, a lymphatic with a pin in it from a 

 neighbouring gland, perhaps the thymus; 31, a lymphatic from the neck, &c. 

 it is divided and enters the jugular by two distinct branches under the sacculus 

 43; 32, the lymphatic from the right side of the head; 33, the lymphatic 

 from the right fore leg; 34, the large sacculus, or receptacle of the lymph, on 



