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COMPARATIVE ANATOMY 



FIG. 326. DIAGRAM OF STAKES IN THE DEVELOPMENT OF THE VEINS IN ELASMO- 

 BRANCHS. (I XI after Rabl, XII after F. Hochstetter. ) 



Ca, Cp, anterior and posterior cardinal veins ; Cdv, caudal vein ; Cl, region of 

 the cloaca ; DC, precaval vein or sinus ; D, D, vitelline veins ; H, sinus 

 venosus of heart ; J, subintestinal vein ; Jr. V, interrenal vein ; LI, hepatic 

 veins ; Npf, renal portal system ; Os, Od, left and right omphalo-mesenteric 

 veins ; Sbc, subclavian vein ; VP, hepatic portal vein ; Vpo, capillaries of the 

 hepatic portal system ; *, hepatic sinus ; f, cardinal sinus. 



the main trunk of the left omphalo-mesenteric vein breaks up into 

 hepatic capillaries, which again unite anteriorly, opening into the 

 proximal ends of both these veins. The latter thus give rise to 



