HO ALLEN 



edge of the second branchial levator muscle, makes a curve at 

 right angles to pass obliquely ventrad along the inner surface of 

 the second branchial levator muscle, where it shortly bifurcates 

 at right angles, one fork continuing obliquely ventrad terminates 

 in the dorsal arm of the great bend of the combined trunk from 

 the third and fourth arches, while the other fork passes dorso- 

 cephalad for a short distance and receives a large communicat- 

 ing branch from the combined trunk of the third and fourth 

 arches, thus forming trunk (#), which, after bending at right 

 angles, passes dorso-caudad to discharge itself in the cephalic 

 trunk, a little behind the hyo-opercularis sinus. As on the 

 opposite side, the ventral fork of the second branchial lymphatic 

 trunk empties into the ventral fork of the cephalic trunk. 



Only a few of the so-called lymphatics from the branchial 

 arches have been traced out, and they either terminated in the 

 main branchial trunks or in the ventral fork of the cephalic 

 trunk. In Fig. 3 the trunk from the first arch culminated in 

 the ventral fork of the first branchial trunk, at a point indi- 

 cated by r.A.L.7\(i) 9 and the one from the third arch 

 (Br.A.L.T.(3)) ended in the ventral fork of the cephalic 

 trunk, directly above the opening of the ventral fork of the sec- 

 ond branchial trunk. 



Ventrad, the termination of the first two branchial lymphatic 

 trunks in the inferior jugular are practically the same for all 

 the specimens, but considerable variation exists in regard to 

 the endings of the third and fourth trunks, both in different 

 specimens and on the opposite sides of the same specimen. 



As shown in Fig. 5 the first and second branchial lymphatic 

 trunks (Itr.Z,.T.(i) and (2)), in their ventral course, finally 

 get to lie immediately behind their corresponding afferent 

 branchial arteries. When close to the ventral aorta, the sec- 

 ond trunk crosses over the ventral surface of the second 

 afferent artery, then passing cephalad, in close proximity to 

 the ventral aorta, it crosses below the second obliquus ventralis 

 muscle to anastomose with the first trunk. Both the first and sec- 

 ond branchial trunks communicate above with the inferior jugu- 

 lar. The former connection (Figs. 5, 6 and 7, Hr.L. T.(i) V.O.) 

 leads up between the sterno-hyoideus tendon and the ventral 



