1401 
“besteht vielmehr aus einer einheitlichen Massa, die oft die Form 
“eines nach hinten offenen Hufeisens hat”. 
Indeed the massive brain matter often has the form of a horse- 
shoe, but it results from two hemispheres, altered in their natural 
direction and united at the frontal pole. In all cases which I 
examined there existed two hemispheres. 
On the other hand I can agree with another quotation of the 
previously mentioned investigators: ‘dass die Blase tatsächlich der 
“Zwischen-hirndecke entspricht, geht aus ihren Anheftungspunkten 
“hervor. Es sind dies Randbogen, Taenia Thalami und Commissura 
“posterior”. 
With this thesis, also defended by Kerprar, | concur in so far, that 
the dorsally prominating sac is not always formed by the roof of 
the IIId ventricle in its total extent. It not seldom occurs that only 
the froutal part of this roof forms the prominating sac. 
In the brain, described in details in the Folia neurobiologica, the 
insertion of the sac however could be followed from the lamina 
terminalis, along the foramen Monror on the taenia thalami to the 
posterior commissure. In the case described by Davipson Brack and 
in the brain of the eyelopian calves the insertion of the sac begins 
on the lamina terminalis, bending with the latter round the very 
wide foramen Monror to continue afterwards on the taenia thalami. 
Then however the distal part of the roof of the mesencephalon rests 
unaltered and does not partake of the promination. 
In the case of Dr. Merman too the sac is present and although 
the insertion is not described, the excellent photos which are added 
to the paper, prove that there too the sac is protuded between the 
two hemispheres, deviating widely and united together at the frontal 
part. 
Not in accordance therefore is the supposition that the ring- or 
horse-shoelike eyclopian brain is formed by an undivided vesicle of 
the hemispheres. Both the halves of the hemispheric vesicles are 
present, but they are placed obliquely cr even transversally to each 
other and they are united to each other in an undivided pole. 
At the frontal pole the bulbus and olfactory tract are missing, 
and certainly frontal arhinencephalia exists. Moreover the anterior 
horns of the lateral ventricles have joined each other, but distally 
from the foramen Monror there appear in all my cases two totally 
separated hemispheres with more or less well-developed walls, in 
which can be distinguished a lateral ventricle with an inferior and 
a posterior horn, a hippocampal fissure and a calcarine fissure. 
l insist upon these facts, because they force me to join the effort 
