DISTRIBUTION OF SUBCUTANEOUS VESSELS IN GANOIDS 9! 



with blue and the veins with a nitrate of silver solution it was 

 conclusively proved from a histological standpoint that these 

 two systems were always distinct, often running side by side 

 and entwining, but never anastomosing. 



Like Neuville, Vialleton included only the viscera in his stu- 

 dies and devoted the first part of his work to a most excellent 

 account of the history of the lymphatics of fishes. In review- 

 ing Sappey's memoir (p. 392) he stated that the numerous anas- 

 tomosing of the subcutaneous lymphatics with the veins, and 

 the origin of certain lymphatic twigs from veins leads one to be- 

 lieve that the vessels described by Sappey as lymphatics are 

 veins. It should be remembered, however, that Sappey used 

 mercury for his injecting mass ; hence it would not be surpris- 

 ing if these connections of the minute lymphatics with the veins, 

 reported by Sappey (p. 24) in the abdominal region, are arti- 

 facts formed by the extravasations of the injecting mass. 



Hopkins' most excellent paper on Amia (8) is to my knowl- 

 edge the only work that has appeared on the Ganoids. 



He finds that each lateral lymphatic trunk terminates ante- 

 riorly, in front of the pectoral arch, in a cephalic sinus, which 

 extends from the clavicle into the base of the cranium, where it 

 could be traced to a point opposite the orbit. About i cm. 

 cephalad of the clavicle there is a valve, which closes an open- 

 ing that leads ventrad into the jugular vein. Posteriorly each 

 lateral trunk ends in a caudal sinus, which is located under the 

 last vertebrae. Each sinus has a cephalic connection with the 

 caudal vein, the orifice being guarded by a valve, and there 

 are said to be at least two communications with its fellow sinus. 

 The dorsal lymphatic trunk terminates anteriorly in the cephalic 

 sinus, and posteriorly into one of the laterals after the latter 

 bends to enter the caudal sinus. Hopkins is not positive 

 whether this trunk bifurcates posteriorly with each fork termin- 

 ating in one of the laterals or not, but thinks that it does. Ac- 

 cording to the writer the ventral trunk begins in the tail and 

 communicates through a cross vessel with the lateral (Fig. n, 

 /). It collects the lymph from the anal and the ventrals, and 

 in the neighborhood of the heart it forks, the two branches 

 merging into the pericardial sinus, which discharges itself into 



