210 



THE FROG— THE PLATANA 



[In the Platana — 



1. The carotid arch gives off: 



(a) Two arteries having a common point of origin near the carotid gland. 



One supplies the floor of the lower jaw, and may therefore be called the 

 " lingtial " artery ; the other supplies the mylo-hyoid muscle. 



(b) A carotid artery passing to the head. It has, at its origin, a slight swelling, 



the carotid gland. 



2. The systemic arches run backwards on each side of the body, meeting 

 posteriorly to form the dorsal aorta. From each systemic arch an artery arises 

 which has the following branches : — 



(i) A scapular artery to the pectoral girdle. 

 (ii) A cutaneous artery to the shin. 

 (iii) A brachial artery to the arm. 



Trace the dorsal aorta backwards, and note that it gives off the cceliaco-mesen- 

 teric artery about midway between its origin and the origin of the first pair of renal 

 arteries. The dorsal aorta then passes between the kidneys, supplying four renal 

 arteries to each kidney, and posteriorly it divides into two internal iliac arteries to 

 the legs. Each internal iliac gives rise to a branch which divides into : 



(i) An iliac artery to the muscles round the ilium. 

 (ii) A cutaneous artery to the skin of the body, just anterior to the leg. 

 (iii) A small artery to the dorsal surface of the leg. 



ual 



Lingual 



Carotid gland Xingual 



Carotid.^ 



Right Auricle. 

 Occipito- v^tebral 



Ca'otid gland 



Right Auricle, 



-Left Auricle 



Pulmo-cutaneous arcli - 

 'Cutaneous 

 Subclavian 

 Pulmonary 

 Ventricle 



Cutaneous 



Pulmonary 



Systemic arch 

 Coeliaco-mesenteric 



A B 



Fig. 72. — A. Arterial System of Mmw, ; and B. of Xenopus. 



