50 ALLEN 



having 3 longitudinal lateral lymphatic trunks, and since the 

 middle one is the largest and is connected with the venous 

 system at either end Trois is right in attributing only secondary 

 importance to the other two. Trois also noted the knotty ap- 

 pearance of the main lateral trunk in Uranoscofius (29, p. 

 21-2) which he thinks is due to rudimentary or imperfect valves 

 that may have been put out of action by death, and the difficulty 

 that he has experienced in injecting this trunk he ascribes to the 

 resistance of these valves. This knotty appearance of the lateral 

 trunk was also noticed in Scorficenichthys, but since no trace of 

 valves has been found it seems best to attribute it to the outside 

 resistance of the body musculature, rather than to the existence 

 of hypothetical valves. To a considerable extent this arrange- 

 ment may check the flow of the lymph and also the injecting 

 mass, but by swelling out in the region of the centers of the 

 myotomes it considerably increases the capacity of the lymphatic 

 system. With the carp and pike Sappey (25, p. 41, and PI. XII, 

 Fig. 2) describes and figures the lateral trunk as bending ventrad 

 about 15 or 20 mm. in front of the clavicle and emptying directly 

 into the jugular without forming any sinus. Hopkins (8, p. 

 371-2) in addition to describing the ordinary termination of the 

 lateral trunk in cephalic and caudal sinuses says that in Am/a 

 this trunk receives a branch from the pectoral sinus before pass- 

 ing under the pectoral arch to open into the cephalic sinus, 

 which is said to extend from the dorsal end of the clavicle to 

 the base of the skull, and which empties into the jugular about 

 1 cm. cephalad and a little ventrad of the dorsal end of the 

 clavicle. 



The lateral lymphatic trunk of Scorfiamichthys (Figs. 1, 4, 5 

 and 6, L..JL. V.) in the trunk region corresponds in the main 

 with the descriptions of the previous investigators. As has 

 already been stated in the general survey of the lymphatics this 

 vessel lies beneath the skin in the median lateral line, and ex- 

 cept in the cephalic portion of the trunk follows parallel, but 

 mesad of the lateral line canal. It is distinctly a superficial 

 vessel lying in the connective tissue septum that separates the two 

 halves of the great lateral muscle. Throughout its entire course 

 it takes up numerous dorsal and ventral intermuscular or trans- 



