Herbert M. Evans 207 
closer in these vessels than in the smaller ones, a fact which seems in 
accord with the greater thickness of the lymphatic walls. It is in vessels 
similar to that shown in this figure that one may find sometimes com- 
plete arterial rings from which capillaries are given off. 
lA COMPANY INE Vern 
Fie. 13. Cross-section of lacteal from the mesentery of the lower jejunum 
of man. X 100. c=Capillaries, vasa vasorum. 
Fig. 12 shows one of the largest ducts near the superior mesenteric 
trunks. The supply is bilateral and one sees here also an alternation of 
arterial and venous stems among the vasa vasorum. It is significant that 
the plan involves merely an increase of that shown in Figs. 2 and 5. 
There is seldom any tendency to form more than this one plexus in the 
