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Show 38 H/rlory of tbs Lactcrzls and Lyntp/mtics. History nftbc Lactcals and Lymp/Jaz‘ics. of the same system. On the other hand, Asellius had an idea thatliis vessels were formed only for the purpose of carrying the cliyle into the blood; he had no conception of their C ting any where else; so that, without the disco- ye oftlie lymphatics, we must have remained ignorant of the greatest part ofthe absorbent . "tent; and therefore they are equally entitled to the honour bestoned on discoverers ofso important a part of our machine. The three first of these anatomists not only found Asellius's vessels in a great many other parts, but they corrected his error in making the lacteals go to the li\ er; and they found out the trunk Ofthc system. They also de- monstrated all this in the human subject. It does not appear, hcwever, that they understood the lymphatiesto be exactly the same vessels as the lacteals. Riitlbeek thought that they absorbed, as Asellius had asserted and proved of the lactcals; at least he comes very near the doctrine; but pro- 39 uniformity of nature, in doing the same thing, in all the different classes of animals, in the same way. Mr. Hunter first discovered them in crocodiles, and in geese. Mr. Hewson first discovered them in turtle, and believed he first saw them also in fish. Thomas Bartliolin, however, claims a prior right to the last, if we are to give him credit, having seen those vessels in the globe fish : " Fide mea apud tc, mi Horsti, exciderim nisi in omnibus animalibus reperiantur maximis minimisque; iii ipsis quoqne piscibus,quod ORBIS cxemplo quidem demon- straVi," Haller also mentions this; and, speaking of Bartholin, says, " Ex arlic' pisce lactea ad hepar euntia descripsit." Haller, at one time, entertained doubts of the existence of these vessels poses it rather as something he suspected, than a thing he was certain of. in other parts of the body than where they had been seen; and thought. " ltahmc quoque vasa, ad aliqua muiicra obeunda extructa fuisst. arbitor- them, to the last, too inconsiderable to perform alone so important an of- fice as absorption. intns excavaia et fistulosa sunt, infinitas habentia vah'ulas, ne humor c glan- " Respondcbimus interim," says he, " resorbtionem peragi ubi nunquam dulis vel aliis partibns art/tins iterum refluat." Bartholin, whose doctrine was better known, and more commonly re- ceived, though he was perfectly satisfied as to the origin and functions of the lacteals, had doubts respecting the origin and functions of the lympha- tics; for he says, " Exortus lymphaticoruin vasorum est ah externis par- tihus, sen, artubus, et visceribus, liepate nempe vesicula fellis, &c." " Qua partc ex artubus prodeant, an a venarum extremis, vel inusctilis, nee dumoculis assequi potuitob vasorum subtilitatem. Conjecturae si quis locus, 21 partibus nutritis debent emcrgere ob usum postea asserendum, quanquam nee a venis capillaribus impossibilis sit exortus." " Qui in nervis circulationcni adniittunt nullam commodiorem haec Viam iii\‘eiiient," The absorbents have since been found in other classes of animals; but had they never been found in any other, it could not have, with any propriety, affectttl our reasonings on men and quadrupeds, where we knew they_ 'aCtually _ existed, and where tl lcll‘ function appears to be as certain as , their existence. . , All that we have gained by the discovery ofthese vessels, in amphibious animals, birds, and fishes, is the proof of the siinpl ieity and uniformity certa fide Ejusmodi \‘asa ostensa stint ut in eercbro, pleura, peritonteo ct cute." Again 2-" Sed neque oculornm lymphatica vasa in nuperis experimentis aut meis aut Zinnii clarissimi adposuerunt-mcdulla? spinalis aquosa vasa nondnm satis itcratis periculis confirmata habemus." " In capite, et artubus pauca." " In vola mantis, dorso pcdis, dorso trunci, natibus nulla omnino (le- scripta." And, lastly,--" Deinde fateri oportet, post lot industriorum viroruin labores fi'agmcnta tamen esse, ea oiiinia (111$ dc vasis lymphaticis sciinus, neque ullo modo cum arteriorum ct venaruni, atit nervoruin historia de~ seriptiones yasorem aquosorum comparari posse." Later writers than IIaller have also treated the lymphatics and lacteals, or real absorbents, as a trifling appendage of the red veins. CHAP. |