594 AMPHIBIA. 
external carotid to the mouth and the orbit, and an internal 
carotid to the brain. 
II. The systemic arch, the median one of the three, 
corresponding to the second efferent branchial in the 
tadpole, gives off— 
The laryngeal artery to the larynx ; 
The cesophageal to the cesophagus ; 
The occipito-vertebral to the head and vertebral column ; 
The subclavian or brachial to the fore-limb. 
From the left aortic arch, just as it unites with its fellow 
of the other side to form the dorsal aorta, or from the’ 
beginning of the dorsal aorta, there is given off the cceliaco- 
mesenteric to the stomach, intestine, liver, and spleen. 
Farther back the dorsal aorta gives off— 
The renal arteries to the kidneys, and the genital arteries to the 
' reproductive organs; | 
The inferior mesenteric to the large intestine. 
Then it divides into two iliacs, each of which supplies the bladder 
(hypogastric), the ventral body wall (epigastric), and the leg (sciatic). 
III. The pulmocutaneous arch, the most posterior, 
corresponding to the fourth efferent branchial in the 
tadpole, gives off— 
the cutaneous artery to the skin, 
and the pulmonary artery to the lungs. 
The venous system.—I. Each superior vena cava is 
formed from the union of three veins, and each of these 
three is formed from two smaller vessels. 
External ace from the mouth and tongue. 
jugular. Mandibular from the lower jaw. 
Internal jugular from the inside of the skull. 
Superior | Innominate. 4; Subscapular from the back of the arm and 
vena cava. the shoulder. 
Brachial from the arm. 
Subclavian. + Musculo-cutaneous from the skin and sides 
\ , of the body. 
” 
II. The inferior vena cava begins between the kidneys, 
and ends in the sinus venosus.. Its components are as 
follows :— 
Inferior 
Genital veins from the reproductive organs, 
vena cava. 
Efferent renal veins from the kidneys. 
Efferent hepatic veins from the liver. 
