844 ANATOMY AND PATHOLOGY 
Table IV. — Taxonomic Classification & Prevalence of Arterial Lesions in Non-Human Primates 
Number of Animals % of Aorta Containing Lesions 
With 
With Fatty 
Fibrous 
Order Common Name 
Scientific Name 
Total 
Lesions Atheroms Steaks 
Plaques Other 
Primates Moneoose 
Lemur mongoz 
1 
1 
4 
Ring-tailed lemur 
Lemur catta 
2 
Slow loris 
Nycticebus coucang 
1 
Senegal bushbaby 
Galago senegalensia 
2 
Douroucouli 
Actus trivirgatus 
7 
1 
tr 
Red uakari 
Cacajao rubicundus 
4 
2 
tr, tr 
Red howler 
Alouatta seniculus 
7 
6 
tr, tr, tr, 1, 2 
Brown capuchin 
Cebus apella 
4 
1 
tr 
Squirrel monkey 
Saimiri sciureus 
14 
13 
1 tr, tr, tr, tr, tr, 3, 3 
10, 15, 40, 6, 7, IB 
tr, 3, 3 
Spider monkey 
Ateles geoffroyi 
1 
Golden lion marmoset 
Leontideus rosalia 
1 
1 
1 
Cotton-top tamarin 
Leontocebus oedipus 
2 
Geoffrey's tamarin 
Leontocebus geoffroyi 
1 
White tamarin 
Leontocebus melanoleucus 
1 
1 
tr 
Pig-tailed macaque 
Macaca nemestrina 
3 
2 
tr, 5 
Rhesus macaque 
Macaca mulatta 
2 
2 
1 tr, 5 
1, 15 
Black ape 
Cynopithecus niger 
1 
1 
tr 
Anubis baboon 
Papio doguera 
26 
16 
tr,tr,tr,tr,tr,tr,tr, 1, 
1. 1, 1, 2, 2, 10, 10, 
tr, tr, tr, tr, 
2, 2, 2 
Grass monkey 
Cercopithecus aethiops 
1 
Mandrill 
Mandrillus sphinx 
1 
1 
tr 
Moustached monkey 
Cercopithecus cephus 
1 
1 
3 
2 
De Brazza's monkey 
Cercopithecus neglectus 
1 
White-nosed guenon 
Cercopithecus nictitans 
1 
1 
tr 
2 
Talapoin monkey 
Cercopithecus talapoin 
2 
Patas monkey 
Erythrocebus patas 
2 
2 
tr, tr 
Black & White colobus 
Colobus polykomos 
3 
2 
tr, 4 
tr, 2 
Red colobus 
Colobus badius 
1 
1 
tr 
White-handed gibbon 
Hylobates lar 
5 
2 
tr, tr 
Siamang 
Hylobates syndactylus 
1 
1 
tr 
Chimpanzee 
Pan troglodytes 
2 
2 
15, 20 
Orang-utan 
Pongo pygmaeus 
1 
1 
tr 
Lowland gorilla 
Gorilla gorilla 
2 
2 
tr, 15 
TOTALS 
104 
63 
2 60 
19 0 
% 
61% 
2% 58% 
18% 
tr := Trace 
mammals, 2 (2%) of 104 non-human primates, 
none of 54 carvivores, none of 12 pinnipeds, 17 
(24%) of 72 birds, and 4 (10%) of 42 exotic 
mammals (Table I). A plaque was called ather- 
osclerotic when focal calcification, necrosis, ac- 
cumulations of extracellular lipid and 'or depos- 
its of doubly refractive crystals were present in 
the central portion of the lesion. The percentage 
of the surface of the aox'tas involved by athero- 
sclerotic plaques could not be readily estimated, 
since the diagnosis of atherosclerosis was 
usually made only after microscopic inspection. 
The individuals with atherosclerotic lesions 
may be found in Tables III-VII. Atherosclerotic 
plaques were usually located in the abdominal 
segments of the aortas. The internal elastic la- 
mella was often fragmented, but was sometimes 
intact, even beneath large atherosclerotic 
plaques. (Figures 5 and 6) No ulcerated athero- 
matous plaques were noted, although one lesion 
in the abdominal aorta of an elderly male rhe- 
sus monkey (Macaca mulatta) contained a cen- 
tral crater-like depression suggesting previous 
ulceration, and similar crater-like depressions 
were seen in plaques of several of the birds. One 
mural thrombus was found on microscopic ex- 
amination loosely attached to a large fibrous 
plaque in the abdominal aorta of an adult fe- 
male ostrich (Struthio camelus) (Figure 7). 
This bird died following surgical correction of a 
prolapsed rectum, so that sepsis may have been 
responsible for the thrombus. This was the only 
mural thrombus found in the entire study. 
Medial Lesions: Various types of medial le- 
sions were found in several species (Tables III- 
VII). Multiple saccular aneurysms were pres- 
ent in the thoracic aortas of two elderly black 
bears (Ursm americanus) . The mouths of 
these aneurysms measured from 5 to 25 mm. in 
diameter (Figure 8). The aneurysms were ap- 
