2 54 THE SALAMANDER 



The peri-ana/ sinus (s.ly.pan.), as its name suggests, surrounds the 

 posterior end of the rectum, and lies between this portion of the gut 

 and a sheath of fibrous tissue. It communicates ventrally with the 

 vesicular sinus, dorsally with the subvertebral sinus, and laterally 

 with the renal sinuses. 



Panizza saw a part of the cloacal vessels and described some of 

 the connexions between the lymphatics of the anus, cloaca, and 

 bladder. Hoyer and Udziela commenting on his account state 

 that these connexions are very much smaller and less important in 

 the larva. 



The caudal lymphatics have been described in considerable detail 

 by Favaro for Salamandra atra. In the adult the main lymphatic 

 trunks of the tail are the subvertebral vessels which run in the 

 haemal canal and form a ladder-like network around the caudal 

 artery. (According to Favaro there is only a single subvertebral 

 trunk in the tail of Triton.) They are continuous with the sub- 

 vertebral sinus of the abdomen. In the larva there is also a pair of 

 lymphatic vessels just beneath the skin mid-dorsally and mid-ven- 

 trally — the TT. lymphatici longitudinales dorsales et ventrales, but 

 in the adult only the latter persist, and that only as a very fine vessel 

 passing along the mid-ventral line in the groove between the lateral 

 myomeres. 



D. Lymphatics oj the Trunk and Viscera (see also PI. XVI). 



These vessels have received considerable attention from the 

 earlier workers and have been largely used to discredit Panizza's work 

 by drawing attention to the distortion caused by his use of mercury. 



The lymphatics of the trunk comprise four pairs of longitudinal 

 vessels. 



(i) The Trunci lymphatici longitudinales parabdominales (t.ly.l.pab.) 

 (Grodzinski, in Amblystoma) have already been mentioned. They 

 pass along the mesial edges of the M. rect. abd. superficialis. 



(ii) The TT. lymph, long, parepigastrici (t.ly.l.pe.) (Grodzinski) 

 form a network around the epigastric arteries and veins. They are in 

 communication posteriorly with the iliac and inguinal sinuses and 

 anteriorly with the subscapular sinuses. 



(iii) The TT. lymph, long, laterales (t.ly.1.1.) (Hoyer and Udziela) 

 lie immediately under the skin in the sulci laterales. 



(iv) The TT. lymph, long, subvertebrales (Hoyer and Udziela) are 

 the largest of all and lie immediately ventral to the vertebral column 

 (Fig. 6y, t.ly.l.sv.). 



