PLAl^K 2 



EXPLAXAIION OF FIGURES 



13 Inner layers of a hypogastric artery from a dog 91 liours old. X410. Van 

 Oieson stain. Connective tissne, black; muscle and blood, yellow. 



14 From a hypogastric artery from a dog 91 hours old, showing the obliter- 

 ation of the lumen through vascular connective tissue. X630. 



\'^ Portion of the wall of a hypogastric artery of a dog Ih years oM. xr)2. 

 Connective tissue, black; muscle, brown. 



1() Portion of the vessel shown in figure lo l)ut somewhat more centrally. 

 X<)3(). Van Gieson stain. C'onnective tissue, black; muscle, yellow. 



17 A section of the inner two-fifths of the wall of a hypogastric artery 

 of a hinib 05 weeks old. Xote the extremely folded elastica interna, the absence 

 of an intima, and the iJicscncc of a layer of fibrous tissue between the latter 

 and the elastica as well as iiiiiucrous elastic fibers in the media. X02(). 



502 



