FIG. 23. A. DIAGRAMMATIC FIGURE OF THE HEAD AND ANTE- 

 RIOR PART OF THE BODY OF A 7~MM. TADPOLE, SHORTLY AFTER 

 HATCHING ; SHOWING THE BRANCHIAL BLOOD VESSELS FROM THE 

 VENTRAL SURFACE. THE HEART HAS BEEN REMOVED. 



B. SAME EMBRYO. FROM THE RIGHT SIDE. THE HEART is REP- 

 RESENTED IN SITU, BUT THE EXTERNAL GILLS OF THE FIRST AND 

 SECOND BRANCHIAL ARCHES HAVE BEEN CUT OFF SHORT AT THEIR 



BASES. (After Marshall.) 



A, dorsal aosta. A B, basilar artery. A C, carotid artery. AF.\,A F.2, 

 A F.'S, afferent branchial vessels of the first, second, and third branchial arches. 

 A /*, pulmonary artery. A /?, anterior cerebral artery. A 7\ anterior palatine 

 artery. C/4, anterior commissural vessel. CP, posterior commissural vessel. 

 E F.\, EF.2, EF3, E FA, efferent branchial vessels of the first, second, third, 

 and fourth branchial arches. EH^ efferent vessel of hyoid arch. E M, efferent 

 vessel of mandibular arch. GE, external sills. GM, glornerulus. KA^ seg- 

 mental duct. K P, head-kidney or pronephros. K S.\, KS.3, first and third 

 nephrostomes of head-kidney. L F.4, efferent lacunar vessel of fourth branchial 

 arch. RA, auricle. R V^ ventricle. R T, truncus arteriosus. KZ>, Cuvierian 

 vein. V H, hepatic veins. V K, vein of sucker. V M, mandibular vein. V F, 

 hyoidean vein. 



