The American journal of anatomy . Fig. 22 Dissection cxposinfi tiu icil iuii^ t(riitoi\- of ;i chick embryo of thir-teen davs incuhat ion. Modiflod from a skctcli l)v (!. H. A. Rech. As Campana pointed out, there is no bi-onchial tree of theadult birds lung in the sense in which this designation is used formammals. No bronchial twigs of the adult avian lung termi-nate blindly. On the contrary, there is established a network of 474 WILLIAM A. LOCY AND OLOP LARSELL intercommunicating passages forming bronchial circuits. Withthis quahfication we may retain the convenient term bronchialtree as app
The American journal of anatomy . Fig. 22 Dissection cxposinfi tiu icil iuii^ t(riitoi\- of ;i chick embryo of thir-teen davs incuhat ion. Modiflod from a skctcli l)v (!. H. A. Rech. As Campana pointed out, there is no bi-onchial tree of theadult birds lung in the sense in which this designation is used formammals. No bronchial twigs of the adult avian lung termi-nate blindly. On the contrary, there is established a network of 474 WILLIAM A. LOCY AND OLOP LARSELL intercommunicating passages forming bronchial circuits. Withthis quahfication we may retain the convenient term bronchialtree as applying to the central trunk and its larger brancheswith their subdivisions, but remembering that the terminal twigsdo not end as in the bronchial tree of manmials. The resem-. Fig. 23 Enlarged view of the lungs of the specimen sketched in figure 22removed from the body. Five air-sacs are shown. The mesial of theinterclavicular not visible. Modified from a sketch by G. H. A. Rech. blance is closer to the capillary connection between arteries andveins than to a tree. From their earliest formation, the lung pouches are lined b}endoderm and this internal cavity is the basis from which hollowbuds arise to form branches of the bronchial tree. The endoder-mal tube lies in a layer of mesenchyme that is bordered on thesurface towards | the pleuro-peritoneal cavity by a well defined THE EMBRYOLOGY OF THE BIRDs LUNG 475 layer of mesothelium. Accordingly, the external boundaries ofthe lung are formed by a wall of mesoderm which gives no indi-cation of the internal configuration of the endodermal formation of the branches of the tree must be traced by re-constructions or by air injections, since the study of the lungs astransparencies, without such in
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Keywords: ., bookauthorwi, bookcentury1900, bookdecade1910, booksubjectanatomy
