1902 - 3 .] Abdominal Viscera of Cercocebus fuliginosus, etc. 521 
tensive and convex. The gastric surface comes next in point of 
extent, and is markedly concave. It looks cephalwards and, to a 
less degree, towards the mesial plane. The renal surface, also 
concave, has not so great a superficial area as has the gastric 
surface. It looks caudalwards and towards the mesial plane. 
The basal surface (Cunningham) is the smallest of the four, and 
is irregularly convex. It is in contact with the small intestine. 
Of the angles, that forming the apex of the organ is the most 
•acute. The anterior (ventral) based angle (Cunningham) is rather 
rounded; and the interned (mesial) basal angle (Cunningham) is 
very poorly developed. The comparative bluntness of the ventral 
basal angle is of some interest, because Cunningham states that, in 
the human subject, it appears to be more strongly marked in the 
foetus than in the adult ; and in the figure of the spleen of Macacus 
■sinieus which accompanies his paper it is decidedly sharper than 
in Cercocebus. 
Of the borders the margo intermedius (Luschka) is the least 
well defined ; only at the apex is it sharp and definite. The 
margo obtusus (Luschka) is much more definite. The margo 
■ erenatus (Luschka) * is convex, and by far the sharpest of the 
three. The term “ crenatus,” as applied to it, is only justified by 
the presence of one notch close to the aj>ex. Comparative freedom 
from notches appears to be a characteristic of the spleen of 
anthropoids ; and it would appear that some of the primates 
lower than the Simiidse also share in this peculiarity; though 
there is evidently much variation in closely allied genera. Parsons 
(24), for instance, gives a figure of the spleen of Cereopithecus 
■callitriehus in which there are three notches. Cunningham’s 
illustration ( Macacus sinieus), on the other hand, shows no 
definite notches. The present specimen from Cercocebus , there- 
fore, stands in an intermediate position. 
The question of the morphological significance of splenic notches 
is one which does not appear to have been satisfactorily answered 
as yet. Parsons (24) has directed some attention to the subject, 
and inclines to the view “ that the notches are mere crumplings of 
* These terms are used, not because they apply in Cercocebus , or, indeed, in 
mammals in general, but because of a reluctance to employ names other than 
those familiar to the human anatomist. 
PROC. ROY. SOC. EDIN. — YOL. XXI Y. 
34 
