1162 SURFACE AND SURGICAL ANATOMY. 
ot the occipital lobe ; the line TR corresponds to the lambdoidal suture, while RO 
corresponds to, or hes a little above, the tentorium and the upper border of the 
lateral sinus. 
CD, the post-central line, corresponds to the superior postcentral sulcus, and lies a 
little behind the inferior postcentral sulcus. 
The parallelogram AMDC overlies the Rolandic area, i.c. the ascending frontal 
and the ascending parietal convolutions, separated by the fissure of Rolando. 
The pentagon ABRPN maps out the temporal lobe, with the exception of its 
ANS a0 
N WY <—— 
% 
Fic. 792.—CRANIO-CEREBRAL TOPOGRAPHY. 
Shows relations of the motor and sensory areas to the convolutions, and to Chiene’s lines. 
G. Glabella. ‘ C.— Mid-point of AB. 
O. Inion. CD is drawn parallel to AM. 
M. Mid-point between G and O. Z. Post-auricular point. 
T. Mid-point between M and O. VW. Guide to anterior limit of lateral sinus. 
S. Mid-point between T and O. Y.  Mastoid antrum. 
EK. External angular process. “I Site at which subarachnoid space may be opened. 
P. Root of zygoma (pre-auricular point). aa Site for draining lateral ventricle (Kocher). 
N. Mid-point of EP. “3 Site for draining lateral ventricle (Keen). 
R. Mid-point of PS. 
apex, which is directed downwards, forwards, and inwards, a finger’s-breadth in 
front of the point N. 
A finger’s-breadth below AB is the parallel sulcus, the posterior extremity of 
which turns upwards to terminate at B, the point which indicates, therefore, the 
position of the angular gyrus. 
The fissure of Rolando may be mapped out upon the sealp by drawing a line 
downwards and forwards for a distance of 32 in. from a point halt-an-inch behind 
