138 



DEVELOPMENT OF THE FROG. 



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

 as yet incompletely developed, are present in the hinder arches 

 as well. 



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

 AF^ from the afferent vessel of the second branchial arch, which 



AP 



EF4 ef:3 ef.^ ef. eh ab e^ 



AC 



Fig. 32. Diagrammatic figure of the head and forepart of the body of a 

 6^ mm, 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 

 l^alatine artery : EFi, EF2, EF3, EF4, efferent ])ranchial vessels of first, 

 second, third, and fourth 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. 



as yet ends blindly. There is also a well-developed efferent 

 vessel, EF^ which opens into the dorsal aorta. 



In the fourth branchial arch there is no afferent vessel, but 



