152 LYMPHATIC SYSTEM. 



though one of them lived an hour, I could not observe any 

 lacteals either upon its intestine or its mesentery. After this 

 I repeatedly examined the intestines and mesenteries of common 

 skate and cod, and at last was so fortunate as to discover the 

 lacteals, and get a pipe into one of those vessels on the mesen- 

 tery of each of these fish ; and, injecting by this pipe, I found 

 where the larger vessels lay ; after which there was but little 

 difficulty in tracing the whole system. I have now seen those 

 vessels in a variety of fish, and shall give a description of them 

 from a haddock. I shall proceed exactly in the order which 

 I have found most convenient for tracing out the whole sys- 

 tem for demonstration, beginning with one of its branches, 

 which, as lying nearest the surface, must, of course, be divided 

 before the other parts can be exposed to view. The account 

 being taken from the fish as it lay on its back, those parts are 

 called superior which are nearest the head ; those inferior which 

 are towards the tail ; those posterior which are towards the 

 back ; and those anterior which are towards the belly. 



On the belly of the fish, exactly in the middle line, is a 

 lymphatic, which runs from the anus upwards ; this lymphatic 

 belongs not only to the parietes of the belly, but to the fin 

 below the anus. It runs up towards the head, passes between 

 the two pectoral fins, and, having got above them, it receives 

 their lymphatics. It then goes under the symphysis of the 

 two bones which form the thorax, where it opens into a net- 

 work of very large lymphatics, which lies close to the pericar- 

 dium, and almost entirely surrounds the heart. This network, 

 besides that part of it behind the heart, has a large lymphatic 

 on each side, which runs upon the bone of the thorax back- 

 wards, and when it has got as far as the middle of that bone, 

 it sends off a large branch from its inside to join the thoracic 

 duct. After detaching this branch it is joined by the lymphatics 

 of the thoracic fins and soon after by a lymphatic which runs 

 upon the side of the fish. This last-mentioned vessel consists of a 

 trunk running on the side just opposite to the ribs, and from 

 this trunk proceed branches on each side immediately under the 

 skin ; so that it has a beautiful penniform appearance. Besides 

 these branches, there is another set, deeper seated, which ac- 

 companies the ribs. After the large lymphatic has been joined 

 by the above-mentioned vessels, it receives the lymphatics from 



