Freiburger historische Bestände - digital

188

Cunningham Memoirs.

on paper, it was measured in the ordinary way. In the foetal and very
young- brains the angle was ascertained on hemispheres removed from the
cranial cavity, and specially prepared with the view of preserving the
external configuration. For these the instrument was equally serviceable.
The following are the results I obtained:—

Eolandic Angle.

Age.

Number

of _
Hemispheres
.

Average
Angle in
Males and
Females.

Limits of
Variation.

Males.

Females.

Number
of
Hemispheres
.

Average
Angle.

Average
Cephalic
Index.

Number

of
Hemispheres
.

Average
Angle.

Average
Cephalic
Index.

Intrauterine Life—



















to Q\ months, .

8

73°-6

72° to 79°













to 7\ months, .

6

73°-5

70° to 79°













to months, .

16

70°-8

65° to 80°

5

74°-4



11

69°-3



Full-time foetuses,

16

70°-6

68° to 75°

13

70°-l



3

73°



Extrauterine Life—



















First 12 months, .

9

70°-6

65° to 76°







9

70°-6

76-2

4 to 5 years, . .

5

70°-6

68° to 73°

4

70°

77-7

1

73°

81-5

11 to 15 years,

7

70°-l

68° to 74°

4

710,2

76-1

3

69°

74

Adult, ....

8

71°-7

69° to 74°

3

73°-6

79-7

5

71°-7

74

Chimpanzee, . .

4

68°















Orang, ....

4

68°















Hamadryas,

1

71°















From the above Table it would appear that the average Rolandic angle
in the adult may be regarded as being 71°'7. The results which I have
obtained in this respect closely correspond with those stated by Eberstaller.
As we have seen, this authority states that in the adult the angle varies from
70° to 75°. I have found the limits of variation to be 69° and 74°. Further,
it will be observed that the average angle may almost be said to be
attained as early as the eighth month of foetal life, and is maintained
from this period up to adult life—another remarkable instance of the