44 



ALLEN 



sinuses surrounding the heart, which would be fatal to a suc- 

 cessful injection. 



The history of the work done on the lymphatics has been 

 given by Milne-Edwards (16), Robin (23), Trois (28), and Hop- 

 kins (8). The general physiology and physiological history is 

 fully set forth in Schafer (26). A recent paper of unusual in- 

 terest is that of F. M. Sabin's " On the Origin of the Lymphatic 

 System from the Veins and the Development of the Lymph 

 Hearts and Thoracic Duct in the Pig" (27). Anything further on 

 the history of the lymphatics of Pisces would be simply repetition. 



2. GENERAL SURVEY OF THE LYMPHATICS OF 

 SCORP^ENICHTHYS. 



As in the higher vertebrates, Milne-Edwards (16; p. 471-2) 

 and subsequent investigators, have separated the lymphatics of 

 fishes into a visceral and a muscular portion, the latter division 

 having been further subdivided into a superficial or subcutaneous 

 and a profundus or submuscular system. These three systems 

 in Scorficenichthys are in close connection. Except in the head 

 region the principal superficial and profundus vessels are longi- 

 tudinal trunks that terminate anteriorly in the cephalic and peri- 

 cardial sinuses, which empty into the jugular near the prootic 

 process and into one of the branches of the inferior jugular ; 

 posteriorly they are collected in the neighborhood of the last 

 vertebra by the right and left forks of the caudal vein. 



The superficial or subcutaneous system of the trunk consists 

 of 4 longitudinal canals, respectively — dorsal, ventral, and 

 lateral. Both of the lateral lymphatic trunks (Figs. 1, 4, 5 and 

 6; JL.L.V.) lie in a median plane, directly beneath the skin 

 in a sheath of connective tissue that separates the dorsal from 

 the ventral myotomes. Posteriorly they unite with the corres- 

 ponding forks of the myelonal lymphatic trunk in the region of 

 the last vertebra, and the combined trunks empty into the right 

 and left branches of the caudal vein. Anteriorly after passing 

 under the shoulder-girdle each of these trunks bifurcates, the 

 lower fork emptying into the pericardial sinus, and the upper 

 after receiving the corresponding fork of the myelonal lymphatic 

 trunk, finally terminates in the cephalic sinus situated under 



