LYMPHATICS IN TAIL REGION, SCORP-ENICHTHYS 27 



One of the Teleosts that swims by a snake-like movement, 

 namely, the eel (Anguilla) has a pulsating heart in the tail. The 

 old view of this heart as presented by Jones (pp. 676-9 and figs. 

 1 and 2) was that it consisted of a single contractle reservoir sit- 

 uated near the end of the tail. No lymphatics were portrayed 

 as emptying into it, but it was represented as discharging its con- 

 tents into the dorsal or minor fork of the caudal vein. In 1905 

 Favaro (p. 571, fig. 1) and in 1906 (pp. 157-168, figs. 64, 70 and 

 71) sets forth a very different arrangement. He finds this heart 

 paired, consisting of an atrium or auricle and a ventricle, which 

 communicate with each other mesad. Anteriorly the atrium is 

 represented as receiving the longitudinal haemal lymphatic trunk 

 and posteriorly the caudal lymphatic trunk, both orifices being 

 guarded by valves; while the ventricle has but one opening, 

 which is cephalad into the caudal vein, and is likewise guarded 

 by valves. This heart is said to possess three tunics, an internal 

 one of endothelium, a median of elastic fibers, and an external 

 of striated muscles. 



In Tinea vulgaris, Favaro (pp. 181-6 and fig. 84, II) finds an 

 arrangement quite similar to the eel. Behind the last vertebra 

 on either side of hypural interval there are two caudal sinuses, 

 which are connected with each other through this interval. One 

 of them the ventricle or ventriculus cordis caudalis opens ante- 

 riorly into a swelling of the caudal vein, the sinus venosus caudalis ; 

 while the atrium or atrium cordis caudalis has two orifices, the 

 anterior receives the profundus portions of the lateral trunks and 

 the posterior the caudal trunk. The latter trunk arises from a 

 sinus, sinus lymphaticus caudalis, situated in the hypural interval 

 at the base of the caudal fin. This sinus is also said to receive the 

 posterior portion of the lateral trunks, and the caudal fin trunks. 

 The latter collect the caudal ray branches from the fin, and are 

 continuous cephalad with the dorsal and ventral lymphatic trunkS; 

 which trunks are said to be but little developed and as in Scor- 

 psenichthys they communicate with the lateral trunks through 

 transverse branches. In Lucius lucius quite a different arrange- 

 ment of the caudal lymphatic trunks is given by Favaro (pp. 196- 

 9 and fig. 107) than was recorded by Sappey, which is to a great 



