CIRCULATORY ORGANS. 305 
There is also a large lymph sinus in the scapular region into which the trunks from 
head and body empty. Frequently there is also a large caudal sinus (physostomes) 
connected with a lymph heart (fig. 310) which forces the lymph into the caudal 
vein. 
The urodeles have the thoracic ducts united behind but separate in front, a 
cephalic trunk emptying into each, and each duct opening into the corresponding 
subclavian vein, while a series of from fourteen to twenty lymph hearts occur in 
connexion with the trunk accompanying the lateral line. The anura are noticeable 
for the complete disappearance of the thoracic ducts, their place being taken by a 
PUY 
SDT pe 
SS area TD 
Fic. 311.—Deeper anterior lymphatics (stippled) of Scorpenichthys, after Allen. a, 
auricle; abs, abdominal sinus; 6, brachial sinus; br, brain; cs, cephalic sinus; d, dorsal trunk; 
Jm, facialis-mandibularis vein; hs, hyoid sinus; 7j, inferior jugular vein; ips, inner pectoral 
fin sinus; j, jugular vein; /, lateral trunk; om, orbito-nasal vein; p, pericardial sinus; p/, 
profundus facialis lateral trunk; pv, profundus ventral trunk; sf, superficial lateral trunk; 
ssl, superior spinal longitudinal trunk; v, ventricle; va, ventral aorta; v/s, ventral fin sinus; 
vp, ventral pericardial sinus; vt, ventral abdominal trunk. 
pair of trunks between the dorsal myotomes and those of the lateral body wall. 
They have also enormous subcutaneous lymph spaces, separated from each other 
by narrow partitions. It is the presence of these large spaces that makes the skin- 
ning of a frog such an easy matter. Two pairs of lymph hearts are present, one 
pair in the neighborhood of the extremity of the urostyle, the other between the 
transverse processes of the third and fourth vertebrae. In the cecilians there is a 
pair of lymph hearts for each segment of the trunk. 
Reptiles have two cephalic lymph trunks and one (lizards) or two thoracic 
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