107 
Biscnorr also thinks that there are monkeys in which the first pli 
de passage is not present. FLargau and JAcoBsoN join in principle 
his view. 
This opinion was attacked by others and in particular it was 
ZUCKERKANDL'), who gave his fullest attention to the plis de passage. 
Not only does he point out, pg. 286, how the 3 outer pli de 
passage, which according to Grationer should be lying on the 
surface, can also be found in the depth of the ape-fissure, but he 
also describes to us a three-rayed figure, which should develop by 
the union of the 1st and 2rd lateral plis de passage and. he plans 
a hypothesis about the way of origin of the 1s lateral pli de passage 
out of the 24, 
As to the presence of the Srd lateral pli de passage in the ape- 
fissure, instead of on the surface of the hemisphere, he points out, 
that this is only possible, when the ape-fissure prolongs in caudal 
direction and is united with the s. occipitalis (0). 
The three-rayed form of these plis 
EA apr ater pi de passages one finds reproduced 
most clearly on his fig. 2, of which 
a reproduction is given (fig. 1). The 
names in it are added to it by me, 
the figures by ZUCKERKANDL. He points 
out, that the first pli de passage (1) 
is curved and the same is also the 
case with the second pli de passage 
(2). In the first the top of the pli 
is, directed medially in the second 
voorvlakte = frontal face * laterally. These two plis de passage 
f- Wweggesneden = resected — continue caudally in one, forming 
CAE ee 1 : a L : a V | IONE 
ai. een VLaGs 1. in this way a three-rayed figure. 
As to the origin of the first pli de passage, ZUCKERKANDL demon- 
strates in first instance on page 293, that the first pli de passage 
can be composed by two pieces; in other words it is a body, which 
only afterwards develops into one and therefore the union of the 
parietal and occipital part of the brainsurface is not primarily, but 
secondarily on that spot. 
On page 296 his view is worked out further. The second pli de 
passage of GRrariorer should form the real primary union and should 
run in oblique direction from the gyrus angularis towards the top 
of the operculum parietale. 
1) ZUCKERKANDL. E., “Zur Morphologie des Affengehirnes.”” Zeitschr. f. Morhp. 
u. Anthr. 1903. 
