1040 
Anatomy. — “On the occurrence of a monkey-slit in man.’ By 
Dr. C. T. van VALKENBURG. (Communicated by Prof. WINKLER. 
(Communicated in the meeting of December 28, 1912.) 
It has long been known that under some cireumstances, in 
case of disturbances in the development of the central nervous 
system of man, a slit may occur on the surface of the occipital 
lobe vividly reminding of the so-called monkey-slit of anthropoides. 
I communicated an example of this fact in a former paper. *) The 
slit then characterized as monkey-slit, answered to the requirement 
that at least part of its orcipital boundary covered convolutions at 
the bottom of the slit connected with the parital lobe (operculation). 
Ermor Situ?) has described the brains of many Egyptians in which 
he very often found (70°/, of the hemispheres) a sulcus simialis sive 
lunatus. BRopMANN*) corroborated this view with the brain of three 
Javanese. On the other hand ZuckERKANDL *) thinks that the exist- 
ence of a monkey-slit in man is by no means proved. As a 
proof he gives a reproduction of some hemispheres in his above- 
mentioned essay. On these surfaces however — of course specially 
selected by ZUCKERKANDL — Eumor SMITH would doubtlessly diag- 
nosticate a monkey-slit. 
How are these contradictory views to be reconciled. We read 
in ZUCKERKANDL’s paper (Le): “Am menschlichen Gehirn soll nur 
“dann von einer Affenspalte die Rede sein, wenn an der Hemis- 
“phärenoberfläche beide Ränder der fraglichen Furche mit jenen der 
“Affenspalte am Affengehirn identisch sind. Trifft dies nicht zu, 
“liegt eine Furche vor, welche nur auf einer Seite (hinten) von einem 
“der Grensränder der Affenspalte abgeslossen ist, während der andere 
“(vordere) nicht mehr dem Gyr. angularis sondern einem Bestandteil 
“der Affenspaltengrube (Uebergangswindungen) angehört, dann hat 
“man es nicht mit der typischen Affenspalte zu tun.” 
1) Van VALKENBURG, Surface and structure of the cortex of a microcephalic 
idiot. These Proc. XII p. 202. 
2) ELuior SmrrH, Studies on the morphology of the human brain. Records of 
the Egyptian Goverumentschool of medicine. Cairo 1904. 
ELLior SmirH, The persistence in the human brain of certain features usually 
supposed to be distinctive of apes. Report of the British Assoc. for the advance. of 
Science 1904, v. 715. 
3) BRODMANN, Beiträge zur histologischen Lekalisation der Grosshirnrinde’ V. 
Journ. f. Psych. u. Neurol. Bd. VL. S. 296. 
4) ZUCKERKANDL, Ueber die Affenspalte und das Operculum occipit. des mensch- 
lichen Gehirns. Obersteiners Arbeiten Bd. XII, 5. 207. 
