592 



AMPHIBIA. 



the red corpuscles often arrange themselves in rows, and 

 the white corpuscles are entangled in the coagulated shreds. 

 When the web of a living frog is examined under the micro- 

 scope, it will be seen that the flow of blood is most rapid in 



CU. 



FIG. 320. Arterial system of frog. 



, Lingual; c. t carotid; j., systemic; cu. y cutaneous; /., pulmon- 

 ary; v.j occipito- vertebral ; br.^ brachial ; c.m., cceliaco- 

 mesenteric; r., renal ; il., common iliacs ; h. y haemorrhoidal. 



the arteries, more sluggish in the veins, most sluggish in the 

 capillaries or fine branches which connect the arteries and 

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

 and are often deformed by pressure ; the leucocytes tend to 



