Robert Bennett Bean 381 
cated by direct measurement from the brain center on the horizontal 
planes. Table IV shows the individual measurements taken in this man- 
ner. ‘Table IV? presents the averages. 
TABLE IVa. 
AVERAGE POSITION OF THE FISSURE OF ROLANDO. 
Left Side. Right Side. 
> JN me 
Naor Inferior. Middle. Superior. Inferior. Middle. Superior. 
Caucasian male ......... De a73%e SSS s ROTO Mai ee S8o. | HOGS 
INGETO IMATE fj ses cele es 27 76 88 108 a 87 108 
Caucasian females 2a..... 13 68 83 107 74 82 107 
INIGHeoy AMEN. Coco ode oe aE all 80 90 111 81 86 112 
A difference of 1° may be allowed for the personal equation in these 
measurements, and the female Caucasian measurements may be elimi- 
nated in the discussion, because only three brains of this kind were meas- 
ured. The male Caucasian and the male Negro fissure of Rolando have 
practically identical relative positions, while the female Negro fissure is 
located nearer the posterior end of the brain than is that of the male in 
either race. This would seem to indicate that more of the brain lies 
anterior to the fissure of Rolando in the female Negro than in the males, 
but by actual measurements of the parts there is less (Table V*). This 
apparent discrepancy is due to the fact that the frontal lobes of the female 
Negro are comparatively longer, but narrower transversely, and from 
above downward, than those of the males of the two races. The areas of 
individual brain outlines are found in Table V, and the averages for these 
are in the following table. 
TABLE Va. 
AVERAGES OF AREAS OF THE BRAIN OUTLINES 1N RELATION TO THE FISSURE OF 
RoLAnpo. AREAS IN SQUARE CENTIMETERS. 
Left Side. Right Side. 
EA Anterior. Posterior. Anterior. Posterior. 
Caucasian male ....... 22 146.2 140.5 148.3 1929 
INGgro) Malerneatecss cee 22 146.6 145.0 146.7 145.7 
Caucasian female ...... 3 118.1 116.6 119.1 ESE 
Negro female ......... 10 125.4 122.3 125.1 123.9 
To compile these tables the three outlines, such as are taken for each 
hemisphere shown in Figures 14 to 3, the sulcus centralis was located 
on each of the three outlines, radii were projected on the horizontal plane 
to the inferior end of the fissure, on the vertical, or mesial plane, to the 
