850 
ANATOMY AND PATHOLOGY 
Figure 6. — (Z 481) Goliath heron (Ardea goliath). 
Adult male. 
A. Large atheromatous plaque showing extensive ac- 
cumulation of lipids and vascularization. Weig- 
ert's elastic stain x 25. 
B. Higher magnification showing vascularization. 
Weigert's elastic stain x 160. 
C. Higher magnification showing foam cells and 
cleft-lilce spaces. Weigert's elastic stain x 160. 
(Reproduced with permission from Exp. Molec. 
Path. Academic Press, New York). 
peared to play very little part in the pathogene- 
sis of the elevated arterial lesions observed. 
Fatty streaks were reasonably common in 
hoofed mammals, especially young ones, and 
were seen primarily in the thoracic segments of 
the aortas. Fibrous plaques were common in 
adult hoofed mammals, but were seen almost 
exclusively in the abdominal segments of the 
aorta. Therefore, it would appear that fatty 
streaks did not evolve into fibrous plaques. 
Lipid was found in some of the larger fibrous 
plaques in hoofed mammals, but in these in- 
stances it was distributed throughout the lesion 
and sometimes into the adjacent media, or more 
frequently, was concentrated in the peripheral 
portions of the plaque. Foam cells were almost 
never seen, nor were central accumulations of 
lipid or areas or central plaque necrosis. On the 
other hand, in birds and a few non-human pri- 
mates, areas of central necrosis were not un- 
common, and accumulations of extracellular 
lipid were often seen in these areas. The ques- 
FiGURE 7. — (Z 405). Ostrich (Struthio camelus). 
Adult female. Small mural thrombus loosely attached 
to the surface of a fibrous plaque. H & E x 160. 
