1410 
visible at the frontal pole, although it does not reach the basal 
lamina terminalis and the brain shows frontal arbinencephaly on 
both sides. 
Those who accept as essential in cyclopia the loss of germ-material 
at the frontal pole, caused (either by a primary defective germ, or 
by a pathologie moment acting on it directly), must not only account 
for the difficulty, which gives the interpretation of the dorsal sac, 
the hydropiec protruding roof of the III¢ ventricle. They too have 
to make acceptable: 
a. why often a total development an internal nose appears in 
the proboscis ; 
b. why under certain circumstances, the sagittal fissure in the 
telencephalon, notwithstanding the arhinencephalia, still develops; 
c. why there is, under circumstances, a burst at the distal base 
of one of the hemispheres. The result of the rupture through the 
frontal poles, which being pressed together, unite again, is obvious. 
But sometimes in one of the hemispheres also a rupture in the 
base of the temporal and occipital parts is demonstrable. 
In short, by the examination of different eyclopian brains particu- 
larities appear, which agree with the old conception of Kunprar. 
SCHWALBE's verdict: ‘Mit dem Zeitpunkt der Bildung der Grosz- 
hirn-hemisphären ist die teratogenetische Terminationsperiode der 
Miszbildungen gegeben, die ein emfaches Vorderhirn haben” — 
cannot concern the eyelopian brain. Cyclopian brains always possess 
two distinct hemispheres, they are only united to one undivided 
mass at their frontal poles. 
