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Show Book ll. ' Of the Llfiigf cf Birds. Expiration is a dim-rent Motion of the Lungs (as following inlpirati on) produced by the Air, after it hath been impelled through Trunks, and van rious Ramulets ofthe A/pem Arteria, and the common Ducts, perforating the Compage, and Membrane of the Lungs) nialtirigaftrorig appulfe upon the adjacent Membrane 3 whereupon its tender Tutti/N being irrita~ ted, draweth its catnons Fibres (derived from the intercof‘t :i Mulllcs ) inm C H‘A Pi XL; 0f the [megs of Birth. to Confent, f0 that thefe fine Engines contraé‘ring, do draw the IVit-riil'n‘ane H E Lungs ofBirds are no lefs admirable than thofe of more perfeét i Animals, in reference to their excellent firuéture, contrived with great artifice ( fpeaking the infinite wifdom ofthe Omnipotent ll'rotoplafi). as they are a rare Syf'ccme, compofed of many pulmonary Arteries and Veins, making numerous Divaricarions, finely wrought in the form of curious Network; and above all, the Afpem Arterizz is divided, and fubdivided into greater and fmaller branches ( the aflbciates of Arteries and Veins) to which are appen- dant many fmall Cells or Veliclesrorf Air, which is difcharged out of the Ramulers ofthe Bronchia, into thefe fruitful Siam, as f0 many receptacles of Breath in Infpiration. This rare Compage of the Lungs of Birds, is chiefly different from that of other. more perfect Animals, as it is affixed to the Back and Ribs 3 Whereas the Lungs of other Animals are left loofe, that they may haveafreedom to be expanded, and contracted in Infpiration, and Expiration 5 but the Lungs of Birds being fafined to the Back and Ribs, have many perforations into the Abdomen, through which the Air bath a free Egrefs and Ingrefs, out and into the body of the Lungs, in Infpiration and Expiration}. The Lungs of Birds are every way encompaffed with a thin denfe Membrane,comp0fed of many Fibrils (running in firaight,oblique,and tranfverfe poi " .. D " 4 Email" "A f, fitions) fo curioufly interwoven with each other, that they feem to be one en- tire picce gas the F ibrils have no vifible Commiffures or Seams, where they are conjoyned. At fome diflance from the 1 rings is feated another more thick and firong Membrane, integrated of greater membranous Fibres, making their pr0< grefs in varionspoliures, and curioufly fet together, interfperfed with many flelhy Fibres (coming from the Ribs, and inlErted into this denfe Mem- brane ) by which this Coat is affixed to the vertebres of the Back. The Air being impelled through the greater and finaller Branches ofthe Bronchia, terminating into common Duéts, which perforating the fubfiance and proper membrane of the Lungs, do tranfmit Air into the Cavity of the Venter, where it is {topped in its current by the interpofition of the Membrane ( adjacent to the Lungs ) as by a Wall. Refpiration in Birds, as well as other Animals, confilteth of a double operation, Infiziration and Expiration, wherein the Lungs are expanded by the reception of Air in the FM}, and contracted upon the exclulion ofit in the Second. Infpiration is performed in Birds by an impulfe of Air, made by the weight of the incumbent Atmofphere,crouding one part after another through the Mouth and A/pcrzz Arteria, as greater Channels into the fmaller PipCS of the Bronchia, through which it is tranfmitted into a common Trunk, (made up of many extremities of Arterial Branches) piercing the Body and Coatof the Lungs, into the empty fpace of the lower Apartiment, wherein the impelled Air fporteth, and expandeth the neighbouring Membrane, wherehv the adjoyning Inteltines, being compreflhd, do relaxe the Abdominal iVi‘Jliilffv Expiration inward, which is aflif'ted by the abdominal Mntcles, pretiing the Intctiines toward the Back, forcing the adjacent Membrane of the 1 rings inward, whereby the infpired Air is repelled through the perforations of the l ungs, and common Duéts, to the terminations of the Bronchia, and from thence through lefs, and greater Branches ofthe Afpem Krrrrz'tz, into the Month. This Membrane encloling the Lungs of Birds at a dil‘tance, and confining the extravafated Air, tranfmitted through the perforated Lungs, is furnilhed with many Henry, and membranous or fine renditions Fibres, making a kind of fine mufcular Expanfion, fupplying the place of aDia~ phragme, and different from that of other more perfetft Animals, upon adouble account, by reafon , Firft this of Birds when relaxed, hath its Concave Surface facing the Lungs, and Convexe toward the Intefiinesa but the Diaphragme of Man and Bealt in its {tare of reflitution, hath its Convexe Surface bending toward the Lungs, and its Concave facing the Viftem of the lowefi Apartiment; Again, this membranous Contexture, interlined with fielhy Fibres, may be difcriminated from the Midrifi‘s~ of other Animals, by reafon the Firllt, when it is contracted, leflcns thepe- culiar Cavity, in which the Lungs are lodged; and thereby fqneezeth the extravafated Air into the perforations of the Lungs 5 but the Diaphragms of other Animals, when contracted, doth enlarge the Perimeter of the Thorax in length, to give entertainment to the Lungs, dilated with Air. |