1576 
If one looks at fig. 5 (length of the embryo 15 em., weight 112 
gr.) then ‘theSlabove-mentioned *fissures@can3be plainly distinguished 
from their surrounding. 
The s. interparietalis has become a deep large furrow, which can 
also be said of the lateral part (m) of the s. par. oce. lat. The 
difference between fig. 4 and 5 therefore is, that on 4 only the 
medial part (m’) of the s. par. occ. lat. has developed into a deep 
fissure, and the rest (lem) is but indicated, while on 5 the whole 
of the /+e+m-+m’ has become a deep fissure. 
Moreover it is proved by the figure that medially from m’ a wall 
is beginning to develop (at the right marked by +), which separates 
m’ from the medial edge. 
If one draws the hemispheres carefully apart, then one finds on 
the mesial face, in the depth, inferior-posteriorly from the splenium 
corporis callosi, a starlike fissure i.e. the union of the fissura cal- 
carina and a superficial small furrow, the s. par. occ. med. 
In fig. 5 therefore it is proved that the sulci interparietalis and 
parieto. occ. lateralis, commence as one furrow and are totally 
separated from the sule. par. oce. medialis. 
Still more distinetly this is proved in fig. 6 (embryo length of 
18 em, weight 172 ger), where the deep incision has developed 
into a suleus. One sees clearly the suleus interparietalis (/ + e) 
‘which forms a whole with the s. par. oce. lat. (m + m'). The s. 
par. occ. med. (w) too is strongly developed and appears on the 
lateral surface as an incisure (7). 
The three sulci, which have so often been brought in relation 
with the ape-fissure, are found here by the side of each other, 
ie. the He, the m + m* and the w sulcus. 
