separate the parietal from the occipital part, should slightly cut into 
the mesial brain mantle and should go lateralwards nearly unto 
the edge of the hemisphere. 
Where this suleus approaches the medial-edge it is divided dicho- 
tomieally into two parts, thus giving an opportunity to form the ‘‘premier 
pli de passage interne supérieur” of GratioLer. Nasal of this dicho- 
tomic division one finds in their drawing (Plate II fig. 2 sub 16) 
the sule. parieto-oec. med. (w), which does not cut into the lateral 
face. Accordingly they do not bring this w suleus in connection 
with the ape fissure. 
CUNNINGHAM *) on the other hand thinks this suleus principally 
formed by the sule. parieto-occ. med. (w), whilst KükeNruar and 
ZivHEN *) deem it necessary that the different sulei / + e + m + im’) 
together help to compose the ape-fissure. 
Nevertheless these last investigators were those who first of all 
considered the fissura simialis (their A suleus) to be taken for a 
separate sulcus. 
Kon.prucer*) however points out, that the last investigators were 
not always consistent in their description of the A sulcus (ape 
fissure) as they regarded this suleus alternately to be equal with 
the w or the 7 + m’ sulcus. 
Thanks to Konisrucce *) a clear differentiation has been made 
between the fissura simialis and the three already often mentioned sulci. 
On page 241 he explains his point of view and writes: “Wenn 
ein Teil der Gehirnobertliiche sich in die Tiefe sänkt, muss ein 
grosser Spalt entstehen; in diesem Falle wird dann der Spalt durch 
das sich stärker entwickelnde Operculum bedeckt”. 
KourBrvaer therefore thinks, that a deep furrow is formed, and 
according to the comparison which follows what precedes, it should 
occur in the same way as with the Fossa-SyLvu, and so, secon- 
darily be covered by an operculum. 
Kontpruece therefore accepts primarily a curving of the brain 
matter and secondarily the forming of an operculum over the deep 
furrow, which is the result of it. 
Also concerning the relation between sulc. interparietalis (/ + ¢) 
and sule. parieto-oce. lat (me Hmm’) he shares the view of KükENTHAL 
and Zurn. On page 222 he objects to the conception of CUNNINGHAM, 
that the m suleus could be interpreted as: “the incision which 
1) KontpruaGe: Die Variationen an den Grosshirnfurchen der Affen u, s. w, 
Zeitschrift f. Morph. u. Anthr. Bd. VI, 1903. S. 242. 
2) Id. P. 217. 
8) Id. P. 240. 
