130 



DEVELOPMENT OF THE SEOO 



about the jimction of head and body to form the single 

 systemic aorta which supplies arterial blood to all parts of the 

 body. 



Besides the complete sets of afferent and efferent branchial 

 vessels in the first and second branchial arches, similar vessels, 



cF^ EF3 EF-'- ^^■' ^" AB rM| „ 



^f-3 AF.2 AF.i VK 



Fig. 32. — Diagrammatic figure of the head and fore-part of the body 

 of a 6J ram. tadpole, showing the heart, aorta, and vessels of the 

 branchial arches from the right side. The external gills have been 

 removed, x 40. 



A, dorsal aorta ; AB, basilar artery ; AC, carotid artery ; AFi, AF2, 

 AF3, afferent branchial vessels of first, second, and third branchial 

 arches; AP, pulmonary artery; AR, anterior cerebral artery; AT, 

 anterior paJatine artery; EFi, EF2, EF3, EF4, efferent branchial vessels 

 of first, second, third, and fouith branchial arches; EH, efferent 

 hyoidean vessel; EM, efferent mandibular vessel; GM, glomerulus; 

 LV4, lacunar afferent vessel of fourth branchial arch ; RA, auricle ; 

 RV, ventricle ; VD, Cuvierian vein ; VH, hepatic veins ; VK, vein of 

 sucker ; VY, hyoidean vein ; YM, mandibular vein. 



a.s yet incompletely developed, are present in the hinder arches 

 as well. 



In the third branchial arch, there is a short afferent branch, 



