Freiburger historische Bestände - digital

176 Cunningham Memoirs.

localise the position of the fissure of Rolando on the surface of the cerebral
hemisphere at different periods of growth:—

Topography of the Fissure of Rolando on the Human Cerebrum.

Mesial Length of the Cerebrum = 100 ; Lateral Length of the Cerebrum = 100.

Period of Growth.

Number of
Hemispheres
Examined.

Mesial
Fronto-Rolan-
dic Indices.

Lateral
Fronto-Rolan-
dic Indices.

Life.

5% to 6% months, ....

12

52-7

418

uterine

A.

6^ to 7% months, ....

12

56-7

43-2

7-j to 8^- months, ....

20

55-2

42-8

Intra

Full-time foetuses, ....

24

53-5

42-6

e Life.

First year of life (comprising brains of
children from 3 months to 12 months) .

12

52-1

42-8

erin

4 to 5 years, .....

14

52-6

43-3

rant

11 to 15 years,

6

51-8

42-3

Ext:

Adults, ......

82

53-3

43-3

The results contained in the Table were published in the form of an abstract in the
Journal of Anatomy and Physiology (vol. xxv.). Since then I have gone over the
measurements a second time, and added materially to the number of specimens
examined. As might naturally be expected, this has led to a slight alteration of the
figures ; but the difference is so trifling, that the general results are riot disturbed.

This Table speaks for itself, so that little need be said about the various
items which compose it. One point is very remarkable, and that is the
stability of position which the fissure of Rolando exhibits on the surface of
the cerebral hemisphere at all periods of growth.

It will be seen on glancing at the fronto-Rolandic indices that the
changes which it undergoes in its position from the time that it first appears
on the surface of the cerebrum up to adult life are very slight indeed. Its