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been formed through the missing of the ethmoidal bone and of 
the mesial wall of the orbit. 
On removal of the brains one is directly struck by the presence 
of the sack (fig. 26) and the epiphysis lying free, seeming to be its 
point of origin. Behind it one does not find anything of a mesen- 
cephalon or of a cerebellum. The sack continues in occipital direction 
and the tela of the 4 ventricle shines faintly through it (fig. 2c). 
On the other hand both the hemispheres are well developed. There 
is a deep sagittal fissure, in which the dural septum with its sinus 
are found, and which has to be cut away from the crista galli in 
order to make its removal possible. 
Drawing of the basal surface of the monstrosity reproduced in fig. 1. a = the 
thin membrane covering the defect in the pes pedunculi cerebri. 6. ol. = bulbus 
olfactorius. /. ol. = lobus olfactorius. N. // =  nervi optici c. m. = corpus 
mammillare, shining through the membrane. N. VJ = nervus abducens. 
If we examine the basal surface of the brain (fig. 3), then we are 
struck by the presence of two well-developed olfactory bulbs with 
their tract, their lobus olfactorius anterior, posterior and cornu 
Ammonis, in short of a completely developed rhinencephalon. 
There are two N. optici (fig. 3, N. II). The corpus mammillare 
