Freiburger historische Bestände - digital

De. Cunningham—Surface Anatomy of the Primate Cerebrum. 205

absence of the sulcus postcentralis superior in the sixth.* Bischoh°t also
figures the union of the two postcentral furrows in the gibbon. In the orang
the sulcus postcentralis superior appears in the majority of cases to remain
separate, although in one figure by BischoffJ it is represented as being
joined to the sulcus postcentralis inferior. In the gorilla it may present
either condition, § although it would seem that it is more frequently united
than free.||

In the orang and the chimpanzee there is present a condition which seems
to indicate that the sulcus postcentralis superior is composed of two pieces.
In the former (fig. 37, p. 206) these elements (p.2) are distinct and separate,
and lie one above the other and in the same line as the sulcus postcentralis
inferior before it turns backwards and becomes continuous with the ramus
horizontalis. The condition of affairs in the chimpanzee is somewhat
different, but leads to the same conclusion. In both hemispheres of each of
the two chimpanzee brains depicted in figures 35 and 36, the lower of the
two elements which apparently enter into the composition of the ramus
postcentralis superior is directly continuous with the ramus postcentralis
inferior, and the point of junction is indicated by the confluence of the
ramus horizontalis; but above this there is a second upper element which
is united with the lower piece in two hemispheres (viz. the left hemisphere
in figure 35 and the right hemisphere in figure 36), whilst in the other two
hemispheres it is distinct and separate. These latter are the two chimpanzee
hemispheres which I have described as presenting a separate
condition of the ramus postcentralis superior. In this assertion therefore I
am only partially correct, inasmuch as its lower element in both cases is
fused with the ramus postcentralis inferior.

* Das Gibbon-Hirn; "Internationale Beitrage zur wissenschaftlichen Medicin," Festscbrift,
Rudolf Vircbow, &c., Band i., p. 42.

f "Beitrage zur Anatoinie des Hylobates leuciscus," PI. n., fig. 1, aus Abbandlungen der
k. baycr. Akad. der Wiss., 11. CL, x. Band., 3. Abth., 1870.

J" Ueber das Gebirn eincs Orang-outan." Sitzung der Matb.-Pbys., Classe vom 17. Juni,
1876, k. bayer. Akad. der Wiss.

§ Broca, Menioires but le cerveau de l'bomme; publies par la Docteur S. Pozzi, p. 636.

|| Pansch, " Ueber die Furcben nnd Windungen am Gebirn eines Gorilla," Ueber die
mensubenabnlicben Affen des Hamburger lluseums. Panscb und Bolau, Hamburg, 1876.