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shines through the pia mater. One can surely demonstrate the N. 
abducens of the cranial nerves. With the nerve lying proximally 
from this, it is not so. Only after a microscopic examination, it is 
certain that it is the N. trigeminus. Between these two thick nerves 
the base of the brain is formed by a thin membrane, which when 
the brain was removed could only be spared with the utmost care. 
If the sack is opened at its dorsal part and is folded backward, 
there appears a local defect in the brain-base, more than 1 cm. 
wide. There the base of the brain is formed by a membrane, 
1 mm. thick, at the utmost, in which some white nerve strings 
diverge from the mid-line towards a proximally placed mass of 
nervous tissue. This nervous mass, striatum and thalamencephalon 
are shining through the pia mater at.the base in fig. 3. There is an 
interrupted continuation in the brain-base at the level of the pes 
pedunculi. 
The bony base of the brain is very remarkable. The crista galli 
protrudes. On both its sides the lamina cribrosa carries the bulbi 
olfactorii, which send their fila olfactoria through it. Moreover the 
optie foramina are normally formed, together with the frontal part 
of the os sphenoidale. Then however the sella turcica is found missing, 
also the hypophysis. The base of the crane is not massive, but 
movable, as there is a great loss of bone distally from the sella turcica. 
An X-ray photo taken from the upper side makes this obvious. 
Here a large defect in the bony base of the skull appears. The 
caudal part of the os sphenoidale is missing in the mid-line and 
the frontal part of the clivus has fallen out as faras the arch of the 
Atlas. The os petrosum is intact on both sides. There are no jaws. 
Through the loss of the facies orbitalis of the upper jaw the eyes 
have sunk downwards. They are no longer lying in a bony orbit. 
The lamina papyracea of the ethmoidal bone is placed proximally 
from the double eye and therefore easily recognisable in the X-ray 
photo. In this case, it is not because the mesial wall of the orbit 
has been destroyed that the eyes have met one another in the 
mid-line, but because the lower wall of the orbit is absent. 
This ecyclopian monstrosity possesses a complete rhinencephalon, 
but at the same time it becomes synotic through the loss of a 
lower jaw. 
As to the question, what may be the cause of such a monstrosity 
one must acknowledge that immense difficulties arise in defending 
that there was an insufficiency of germ material, as far as the 
brain as well as the bony parts of the skull. is concerned Simpler 
is the view in taking the sack as point of origin. 
