oe 



Fig. 3966. Swimming-bladder (S, anterior, S', posterior, division) of the bleak; 

 as. oesophagus; I, air-passage of the air-bladder leading into the oesophagus. 



Fig. 396c. Circulation of the blood in a bony fish, an, auricle; ven, ventricle; 

 bar, bulbus arteriosus; ao, aorta; 60, one of the four branchial arteries which 

 carry the blood to the gills, and afterwards unite to form the descending aorta 

 (dao); pc, portal circulation; vc, great descending vein (vena cava); kid, kidney. 



Fig. 396d. The structure of the minnow and the living fish. B n. nose; A n, 

 nose-pit; gc, gill-cover; a.f, pectoral or arm-fin; If, leg-fins or ventrals; rf/, dorsal 

 fin; sf, anal tin; cf. < aii(ial fin; MS. mucous scales of the latenil line; e, optic 

 nerve; ea, par-nerve leading from the brain; f/, gills; h, heart; t, oesophagus; s, 

 stomach; fc, kidnev: r. \ent; da, dorsal artery; , air-bladder; b, back-bone; 

 nv, nerve-cord or spinal cord. 



[To fitci- paije 435.] 



