558 PHILOSOPHICAL TRANSACTIONS. [aNNO I768. 



the coeliac artery; these vessels ran behind the cava, and down upon the aorta, 

 near to the origin of the crural arteries, and he presumes they were the trunks 

 of those branches which he had seen in the thigh. At the root of the coeliac 

 artery, and on the contiguous part of the aorta, a network (f f ) is formed by the 

 lacteals and lymphatics above described. This network consists of 3 or 4 trans- 

 verse branches, which make a communication between those which are lateral. 

 In the subject from which his drawing was made, there were 4. From this net- 

 work arise the 1 thoracic ducts (gg) ; of which one lies on each side of the- spine, 

 and runs upon the lungs obliquely up towards the jugular vein, into which it 

 opens (1 and n); not indeed into the angle between the jugular and subclavian, as 

 in the human subject, but into the inside of the jugular vein, nearly opposite to 

 that angle. The thoracic duct of the left side is joined by a large lymphatic (h), 

 which runs upon the oesophagus, and can be traced as far as the lower or glan- 

 dular part of that canal ; from which part, or from the gizzard, it seems to 

 issue. The thoracic ducts are joined by the lymphatics of the neck (and probably 

 by those of the wings) just where they open into the jugular veins. 



The lymphatics of the neck * generally consist of 2 pretty large branches, on 

 each side of the neck, accompanying the blood-vessels. Those 2 branches join near 

 the lower part of the neck; and the trunk is in general as small, if not smaller, 

 than either of the branches. This trunk runs close to the jugular vein (ii), gets on 

 its inside, and then opens into a lymphatic gland (kk). From the opposite side 

 of this gland, a lymphatic comes out, which pours the lymph into the jugular 

 vein. On the left side, the whole of this lymphatic joins the thoracic duct of 

 the same side (1) ; but on the right, one part of it goes into the inside of the ju- 

 gular vein a little above the angle (m), while another joins the thoracic duct, 

 and with that duct forms a common trunk, which opens into the inside of the ju- 

 gular vein, a little below the angle which that vein makes with the subclavian (n). 

 To this description it may be necessary to add, that though it may be taken 

 from one subject, yet in 3 others of the same sjiecies which he examined care- 

 fully, he saw nothing which disagreed with it. He particularly attended to the 

 number of the thoracic ducts, suspecting, that possibly in this subject, the 2 

 that he had seen might be only a variety, which is a circumstance that, as we 

 are told, has occurred even in the human body. But in 3 others of this species, 

 which he likewise successfully injected, he still saw 2 ducts ; and therefore he 

 was inclined to believe, that this is the constant number. He likewise carefully 

 attended to the vessels coming from the gland on the right side . and in the only 

 2 subjects in which the lymphatics of the neck were properly filled, he observed 



* It is but doing justice to the ingenious Mr. John Hunter, to mention here, that these lymphatics 

 in the necks of fowls were first discovered by him many years ago. — Orig. 



