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Proceedings of the Royal Society 
brain I shall designate in the following remarks as yl. By permis- 
sion of Professor Groodsir I have also had the opportunity of exa- 
mining two as yet undescribed brains of this animal, both females, 
in the anatomical museum of the University of Edinburgh. It will 
be convenient to refer to these as B and G. 
In all three specimens the antero-posterior convolutions of the 
frontal sub-division of the frontal lobe corresponded so generally 
in their arrangement with each other, and with the brains of the 
Fig. 1. — Vertex view of the brain A. Fr. Frontal lobe. R, Fissure of Rolando. IP, Intra- 
parietal fissure. P, Parallel fissure. E P, External perpendicular fissure. 4, 4, Ascending- 
frontal gyiTis. 5 5, Ascending parietal gyrus. 5", Inner, 5' , Outer part of postero-parietal 
lobule. 6 6, Angular gyrus. 10, Superior occipital gyrus, a, Superior annectent gyrus. 
B, Second annectent gyrus. 
Chimpanzee figured by Professors Cratiolet and Marshall, that no 
special description is necessary. In all, the olfactory sulcus was 
well marked ; and in two specimens a triradiate arrangement of 
the sulci, situated in the outer part of the lobule, was distinct, 
though in the third specimen (J) this regular mode of arrange- 
ment did not exist. The ascending frontal (premier pli ascendant) 
(4 4) and ascending parietal (deuxieme pli ascendant) (5 5) con- 
volutions also agreed very closely in their general arrangement ; 
