Freiburger historische Bestände - digital

10

Cunningham Memoirs.

distinguish the one from the other, and the constancy and uniformity of
the natural folds serve as a sure means of distinction."* After some
experience there is little danger of confounding an artificial with a
natural enfolding of the hemisphere wall.

In Italy Giacomini,t Romiti,t and Mingazzini § have paid some
attention to the temporary fissures, but in this country little or no notice
has been taken of them. It is true that Callendar,|| in his " Lectures upon
the formation and early growth of the Brain of Man," has referred to them,
but his systematic neglect of the work done by others in the same field
greatly diminishes the value of his observations.

The material which I have had at my disposal for observing the
characters and tracing the history of the temporary fissures has been fairly
abundant. In all I have had fourteen hemispheres which come within the
limits of the prescribed period. The following is a list of these:—

Number of
Hemispberes.

Longitudinal
Diameter.

Probable Period of Development.

2

15 mm.

Latter part of the second month.

2

19 mm.

Beginning of the third month.

4

25 mm.

Between the third and fourth months.

2

27 mm.

First week of the fourth month.

2

28 mm.

First week of the fourth month.

2

33 mm.

Four and a-half months.

* Die Formentwickelung des menschl. Yorderhirns, &c, Des xv. Bandes der Abhandluugen
der Math. Phys. CI. der Konigl. Sachsischen Gesellschaft der Yfiss. No. Tin., p. 694.

f Guida alio studio delle circonvoluzioni cerebrali dell' uomo. Torino, 1814.

X " Sull' ordine di successione, con il quale appaiono le scissure cerebrali," Processo Yerbale
delta Soc. Toscana di Sci. Nat., 1882.

§ " Ueber die Entwicklung der Furchen und Yfindungcn des menschlichen Gehirns." Unter-
suchungen zur Naturlehre des Menschen und der Tbiere, herausgegeben von Jac. Moleschott, xiii.
Band, 6 Heft.

|l British Medical Journal, June 6, 1874.