AETEEIAL SYSTEM 

 1. The afferent branchial vessels. 



231 



The afferent branchial vessels are most readily followed by 

 injecting them from the conus arteriosus, but this must not be 

 done if the heart is to be dissected in the same specimen. 



Fio. 51. — ScylUum canicula. Dissection of the arterial system from 

 the ventral surface. The floor of the mouth has been cut through 

 close to the median plane, and the right half turned outwards, 

 (o. H. H.) 



A, nostril. ATT, auricle. B, rigit orbit. BA, out end of hindmost 

 brEUicMal artery of the right side. BA 1, first branchial artery of the left 

 side. BA 5, fifth branchial artery of the left side. BE, first efferent bran- 

 chial trunk, or epibranchial artery, of the right side. BP, fourth efferent 

 branchial trunk, or epibranchial axtery, of the right side. C, carotid artery. 

 OA, cardiac aorta. D, the fifth or trigeminal nerve. DA, dorsal aorta. 

 B, external carotid artery. Wy internal carotid artery at the point where it 

 enters the cranial cavity. G, the hindmost of the efferent branchial vessels. 

 TT , spiracle. I, efferent branchial loop of the first branchial cleft. K, sub- 

 clavian artery. M 1, first branchial cleft of the right side. M 5, fifth branchial 

 cleft of the right side. 3V, longitudinal hypo-branchial artery. O, connecting- 

 branch between the efferent branchial loops. SV, sinus venosus. T, teeth. 

 V, ventricle. 



