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Show 0f [/20 Lympbzzlics and Laden/x. Rmm/itrations, Autism/1mm, Number, and Size, 88 only inject the courser net-work; the areolae of which, lying in the inter- livill‘llll' stices surrounding the small generally ofa square figure. expresses the appearance by entia." In the lungs ofthe lobules of which the lungs are composed, are This net-work was noticed by Haller; who the words " Vasa concatenata reticulum faci- turtle, the lymphatics form a similar nepwork; but in the lungs of many quadrupeds they ramify, in the usual manner of arteries and veins, without forming any net-work resembling that now de- scribed. In the intestines of the turtle, there is also a very fine net-work of parallel vessels, situated between the muscular and villous coat. \Vhen this is injecred with quicksilver, and the intestine fully inflated and dried, the mercury appears as if extravasated into the cellular membrane, though more regular and uniform; but if, after having injected the net-work, the intestine is inflated only to one third of its diameter, the cylindric vessels forming this net-work, and which are every where of the same diameter, become extremely distinct. I believe that these vessels communicate with one another, either by exceeding short branches, or lateral foramina; for the whole net-work fills immediately and uniformly, after the mercury has once entered it. A similar net-work is to be found on the spleen in calves. The branches of the arteries in the human body so unite with one another, that the arteries of almost the whole body may be injected from any one of the branches. This communication between the branches of the arteries is termed anastomosis. The branches of the lymphatics and lac- tcals also anastomose; so that, did not their valves prevent retrograde motion, what was asserted of the arteries might be also asserted of thEm; that by a pipe introduced into any one of the branches, the greater trunks of the system might be injected. This anastomosis takes place not only between the smaller branches, but between the larger trunks and the glands themselves. It is thence that very many lacteals and glands, and even the thoracic duct itself, may be filled from one lacteal on the intestine. From one lymphatic on the top of the foot, a considerable number of other lym- phatics on the leg and thigh, the greater number of the glands in the groin, on the edge of the pelvis, on the vertebra: of the loins, and the thoracic duct itself, may in the same manner be injected. From one absorbent on nication, was able to demonstrate, at lectures, some hundreds of lympha- tics on the upper surface of the diaphragm turgid with white chyle. In the intestine of the turtle, if the quicksilver can be made once to enter the net-work, all the lacteals of the intestines and mescntery may be injected from it,- and on the lungs I have, from one vessel, actually injected all the. lymphatics of a whole lobe. The intention of nature, by these anastomo_ ses, is evidently to secure a number of roads, by which these important fluids, the ehylc and lymph, may be carried stance I have mentioned, of the anastomosis lymphatics of the liver and diaphragm, the into the blood, were the thoracic duct itself into the blood. In between the lacteals chyle, it is evident, obliterated; for the the in- and the may get lympha- tics of the diaphragm pass under the sternum and cartilages of the ribs, to the angles between the jugulars and subclavians of both sides. Asellius has represented the lacteals in quadrupcds as numerous on the mesentery as either the arteries or veins; and anatomists in general have allowed his representation to be just. In the human intestine, those which I call the deep-seated set, are exactly double the number of the arteries or veins: for every artery is attended with one vein and two lacteals: the artery and the vein lie in the middle, and the lacteals one on each side,- he- sides these, however, there is a superficial set remaining under the peritoneal coat of the intestines, so that the lacteals are three times, if not four times more numerous than the arteries and veins. In the intestines of the turtle, if the net-work is included, the number of the lacteals, in proportion to the arteries and veins, is still greater; so very much so, that I am tempted to suspect that they do something else than absorb cliyle or lymph. Though the lacteals were allowed to be so numerous in many animals, anatomists in general did not believe that the lymphatics of other parts were in propor- tion numerous. the external surface of the liver some hundred of the superficial set may ' be 89 be filled, and a great number even of the deep-seated ones. It has some times happened, that nearly half of the absorbents of the lungs have, in the same manner, been injected from a single aperture in any one of the lymphatics, on their external surface. Some years ago I discovered an anastomosis between the lacteals coming from the mesentery, and the lym- phatics of the liver and diaphragm; and, in consequence of this commu- I have already quoted Hallcr's sentiments on this subject, N declaring |