542 



AMPHIBIA. 



the veins. The red corpuscles are swept along most rapidly, 

 and are often deformed by pressure ; the leucocytes tend to 

 cling to the walls of the capillaries, and may indeed pass 

 through them (diapedesis). 



The Arterial System. 



Each branch of the truncus arteriosus is triple, and divides 

 into the following on each side : 



I. The carotid arch, the most anterior, corresponding 



FIG. 181. Arterial system of Frog. (After ECKER.) 



/., Lingual ; c., carotid ; s., systemic ; cu., cutaneous ;/., pulmon- 

 ary ; z/., vertebral; frr., brachial ; c/m., coeliaco-mesenteric ; 

 r.) renals ; zY., common iliacs ; A., haemorrhoidal. 



to the first efferent branchial of the tadpole, 

 gives off 



a lingual artery to the tongue, 

 a carotid artery, which bears near the origin of 

 the lingual a spongy swelling (the " carotid 

 gland "), and gives off an external carotid to 

 the mouth and the orbit, and an internal 

 carotid to the brain. 



