78 ALLEN 



and each fork after passing along the side of the ventral aorta 

 emptied into the sinus venosus. Following the common stem 

 of the inferior jugular cephalad it will be seen from (Figs. 6, 7 

 and 8) that it may branch and each fork receive first the com- 

 bined sinus-like trunk of the third and fourth nutrient branchial 

 veins and then in succession the second and first nutrient 

 branchial veins as shown by Fig. 8, Nut. V. (S4) , etc.) or as was 

 noticed in other specimens may expand into a broad sinus 

 between the second and third branchial arches, which in like 

 manner collects the nutrient branchial veins. In either case the 

 anterior part of the inferior jugular in spreading out over the 

 thyroid gland took on more the appearance of a lymphatic trunk 

 than it did a vein. • 



9. GENERAL CONSIDERATIONS AND SUMMARY. 



Scorficenichtkys has as complete a lymphatic system as is to 

 be found in any vertebrate ; in general wherever there is con- 

 nective tissue there are lymphatics. As in the higher Verte- 

 brata there are distinct superficial and profundus systems. In 

 the trunk region the main lymphatic canals are longitudinal 

 trunks that terminate caudad in the caudal vein, and cephalad 

 empty in one way or another into the cephalic and ventral peri- 

 cardial sinuses, which ultimately reach the jugular and appa- 

 rently the inferior jugular veins. These sinuses are simply 

 non-contractile reservoirs in no way comparable to the lym- 

 phatic hearts of the Batrachia. In the region covered by this 

 paper no valves were found except at the orifice of the cephalic 

 sinus papilla in the jugular. 



1. The lateral lymphatic canal in the trunk region very 

 closely resembles the descriptions already given for other 

 species. Dorsal and ventral intermuscular or transverse 

 branches were regularly received ; they arose from a network 

 in the connective tissue of the myotomes and skin, and anasto- 

 mosed above with the dorsal lymphatic trunk and below with 

 the ventral trunk. In the anterior region of the trunk there 

 are dorsal and ventral lateral lymphatic vessels, which are 

 merely a series of longitudinal cross-branches, lying above and 

 below the main lateral trunk, but which give additional support 



