AVES. 



243 



Fig. 70. GENERAL DISSECTION OF MALE PIGEON. c, Cere, close to which 

 is external naris, ex.n. ; u.gl, opening of uropygial gland; il, cut edge 

 of ilium ; st, keel of sternum. A large part of this bone has been 

 removed together with ribs, b, Beak ; t, tongue ; p.n, internal nares ; 

 rjl, glottis ; ffi., gullet, which swells into the crop in the middle of its 

 course ; pr, proventriculus ; gz, gizzard ; d, duodenum. Most of 

 ileum has been cut away, at i its junction with large intestine is seen. 

 This point is marked externally by the intestinal caeca, one of which is 

 shown ; cl, cloaca ; /. I, placed on left liver-lobe at point where right 

 lobe was removed ; x , x , placed on points where bile-ducts enter 

 duodenum ; p, pancreas ; ***, placed 011 points where the pancreatic 

 ducts enter duodenum; r.a, right auricle of heart, into which the 

 cavals run ; pr-c, right precaval, formed by the union of (ju) jugular 

 and subclavian, the short vessel just over pr-c. which the brachial 

 ( 1 ) and pectoral (2, 2') veins combine to form ; p-c, postcaval, the 

 other cut end of which is close to t; r.v, right ventricle ; i.a, right 

 innominate artery bifurcating into common carotid above, and sub- 

 clavian, the latter at once dividing into brachial (above) and pectoral 

 (below). The dorsal aorta (d.ao) is seen running back from heart. 

 The cut end of the coeliac artery is just above pr, and that of the 

 anterior mesenteric to the right of t; tr, trachea; k, k', k", anterior, 

 middle, and posterior lobes of right kidney cut through ; v.d, right 

 spermiduct (vas deferens), along inside of which right ureter runs ; t, 

 left spermary (testis) the right is removed ; ol, placed over olfactory 

 lobe, and olfactory nerve which runs forwards from it; cJi, cerebral 

 hemisphere; o.l, optic lobe; cb, cerebellum; m.o, medulla oblongata. 

 II. , Optic nerve, just above which is optic tract; sy, right sympa- 

 thetic ganglia of thorax, between which are cut ends of ribs. The 

 ganglia are connected by double commissures, which, with connected 

 nerve branches, are represented by black lines. 



