THE CCELOM 



39 



thence diverging to be attached ventrally to the sternum 

 along two lines, one on each side, set obliquely to the median 



Ao 



-' jy 



V.I.I. M '' 



FIG. 23. KESPIRATORY ORGANS OF DUCK. 



/- \', air sacs ; 7V, trachea ; </./, dorsal margin ; v.n.l, ventral margin of lungs ; 1-3, dissepiments 

 between air sacs ; Ao, aorta ; c.a, coeliac artery ; in. u, mesenteric ; m, muscular fibres ono.s, 

 oblique septum ; F^S, vertical median septum : L.c, longus colli; A', kidney. (After HUXLEY.) 



o.s 



2: 



3. 



es. 24. EESPIKATOHY ORGANS OF APTEKYX. LETTERING AS IN FIG. 23 



(AFTER HUXLEY 



