Freiburger historische Bestände - digital

92 Cunningham Memoirs.

eighteen (i. e. 60 per cent.). If we analyze these thirty cases, we find the
following results :—



Right Side.

Left Side.

Male.

Female.

Anterior horizontal limb on the \
orbital face of the frontal lobe >
12 times, . . . . J

Anterior horizontal limb on the ]
outer face of the hemi- \
sphere, 18 times, . . )

80 per cent.
24

20 per cent.
76

60 per cent.
50

40 per cent.
50 „

From this it would appear that the orbital position of the anterior horizontal
limb is more common on the right hemisphere than on the left.

The Y-shaped Condition of the Anterior Limbs.—As Eberstaller has so well
shown, this condition by the shortening or the lengthening of the common
stem exhibits every gradation between the V form of the two separate
limbs and the single anterior limb. It was noted twenty-six times in the
eighty hemispheres examined, i. e. in 32'5 per cent.

The following Table gives the relative frequency of the three conditions
in which the anterior limbs may exist according to sex and side:—

Relative frequency according to Sex and Side of the three conditions of
the Anterior Limbs of the Sylvian Fissure.

Eighty hemispheres examined, viz. 52 male, 28 female; 46 right, 34 left; 64 adult,

16 children.

Condition.

Eight.

Left.

Male.

Female.

Total.

Single anterior limb, . . j
Two separate limbs, . . j
Y-shaped condition, . . j

(19 times)
41-3 p. c.

(15 times)
32-6 p. c.

(12 times)
26-1 p. c.

(5 times)
14-7 p. c.

(15 times)
44-1 p. c.

(14 times)
41-1 p. c.

(16 times)
30-8 p. c.

(21 times)
40-4 p. c.

(15 times)
28-8 p. c.

(8 times)
28-5 p. c.

(9 times)
32-1 p. c.

(11 times)
39-3 p. c.

(24 times)
30 p. c.

(30 times)
37-5 p. c.

(26 times)
32-5 p. c.