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. A F.I, A F.2, 

 A F.3, afferent branchial vessels of the first, second, and third branchial arches. 

 A P, pulmonary artery. A ft, anterior cerebral artery. A T, anterior palatine 

 artery. CA, anterior commissural vessel. CP, posterior commissural vessel. 

 F.I, EF.2, EF.3, E FA, efferent branchial vessels of the first, second, third, 

 and fourth branchial arches. EH, efferent vessel of hyoid arch. EM, efferent 

 vessel of mandibular arch. GE, external gills. GM, glomerulus. KA, seg- 

 mental duct. KP, head-kidney or pronephros. KS.l, A' 5.3, first and third 

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

 arch. J?A, auricle. R V^ ventricle. R T, truncus arteriosus. V D, Cuvierian 

 vein. VH, hepatic veins. V K> vein of sucker. VM^ mandibular vein. VY^ 

 hyoidean vein. 



