rHAX(iES IX FETAL VESSELS OF THE LIVER 



499 



degeneration of the endothelium and the niuscuhiture was 

 present but the formation of i)rocesses was not observed. As 

 shown in figure 1 1 the intima which is absent in places, has under- 

 gone degeneration although the lumen still contains blood. 

 Figure 12 shows a section of the accompanying omphalomesenteric 

 vessel apparently in a more advanced stage of degeneration, for 

 here the whole lumen is obliterated by the large cast-off endothelial 

 cells and fibrin which form a network completely filling it and 



Fig. 1 

 liours ol( 

 X7o0. 





2 Transverse section from an omphalomesenteric, vessel of a dog 44 

 I. Lumen filled with desquamated endothelium and a fibrin network. 



sinmlating endothelial proliferation and migration. In the case 

 oi both these vessels the nmsculature has undergone consider- 

 able degeneration, and readily takes an acidophile or special 

 connective stain, making it difficult to distinguish the connective 

 tissue which is, of course, also a purely temporary constituent. 

 In case of the hypogastric artery of the same dog no process 

 formation is present and the intima has completely disappeared 

 over a considerable extent of the distal ])ortion. The lumen 

 which is not lined by endothelium although containing blood is 



THfc AMERICAN- JOURX VI. Of ANATOMV VOL. IG NO. 4 



