Freiburger historische Bestände - digital

PLATE IL

[A series of Views of the Cerebrum of the Human Foetus at different periods of development. The various figures were

drawn upon the stone from photographs.]

LETTERING COMMON TO ALL THE FIGURES.

/-1 .

Sulcus frontalis primus.

r.2 .

. Lower piece of the fissure of Rolando.

r- .

Sulcus frontalis sectindus.

P- •

. J ntraparietal sulcus.

f. m.

Sulcus frontalis medius.

P-1 •

. Sulcus postcentralis inferior.

p. c. .

. Early sulcus praecentralis inferior.

p."1

Sulcus postcentralis superior.

p. c. i.

Sulcus praecentralis inferior.

P-* •

. Ramus horizontalis of the intraparietal sulcus.

p. c. s.

. Sulcus praecentralis superior.

p.* .

. Ramus occipitalis of the intraparietal sulcus.

F. P.

Fronto-parietal operculum.

e. p. .

. Fissura perpendicularis externa.

F. .

Frontal operculum (pars triangularis).

e. c. .

External calcarine fissure.

0. .

Orbital operculum.

t.1 .

Parallel sulcus.

r.

Fissure of Rolando.

*.2 .

Second temporal sulcus.

r.1 . .

Upper piece of the fissure of Rolando.





[N.B.—In Figures 5, 9, 11, 15, 18, and 20 the dotted outlines in each case indicate the area of cerebral surface

covered by the parietal bone.]

Figure 1.—Foetus in the tenth or eleventh week of development, with the cerebrum exposed in situ.
Figure 2.—Right hemisphere of a cerebrum from a foetus in the tenth week of development.
Figure 3.—Left hemisphere of a cerebrum from a foetus in the twelfth week of development.

Figure 4.—Left hemisphere of a cerebrum from a foetus in the twelfth week of development:—2, the primitive polar
gyrus formed by the insula posterior.

Figure 5.—Right hemisphere of a cerebrum from a foetus in the first half of the fourth month of development.

Figure 6.—Left hemisphere of a foetal cerebrum in the latter part of the fourth month of development.

Figure 7.—Right hemisphere of a foetal cerebrum in the early part of the fifth month of development:—1 and 2, primitive
polar gyri. [Vide p. 102 of the text.)

Figures 8 and 9.—The two hemispheres of a cerebrum taken from a foetus which had apparently reached the second
week of the fifth month of development.

Figure 10.—.Right cerebral hemisphere from a foetus which had probably reached the sixth month of development:—
2, sulcus centralis insulae.

Figure 11.—Left cerebral hemisphere of a foetus at the end of the fifth month of development.

Figures 12 to 15.—Four cerebral hemispheres from female twins which had apparently reached the early part of the
(sixth month of development:—1, sulcus praecentralis insulae ; 2, sulcus centralis insulae.

Figure 16.—Right hemisphere of a foetal cerebrum in the early part of the sixth month of development.

Figures 17 and 18.—The two hemispheres of a cerebrum in the early part of the seventh month of development:—1, sulcus
praecentralis insulae; 2, sulcus centralis insulae.

Figures 19 and 20.—The two hemispheres of a cerebrum in the early part of the seventh month of development:—1, sulcus
praecentralis insulae ; 2, sulcus centralis insulae.

Figure 21.—Left cerebral hemisphere in the end of the sixth or the beginning of the seventh month of development.

Note the development of the hinder transverse gyrus of Heschl (k.), and in connexion with this the terminal bifurcation
of the posterior horizontal branch of the Sylvian fissure. (Vide Eberstaller's remarks upon this, in his article entitled
" Zur Oberflachen-Anatomie der Grosshirn-Hemispharen," Wiener Medizinische Blatter. No. 20, 1884, p. 613.)

Figures 22 and 23.—The two hemispheres of a cerebrum in the early part of the sixth month of development:—
1 and 2, primitive polar gyri (vide p. 102 of the text); 3, the uncus.

Figure 24.—Left cerebral hemisphere in the seventh month of development.

Figures 25 and 26.—The two hemispheres of a cerebrum in the last week of the fifth month of development.
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