841 
sagittalia can cause quadrantic hemianopsia in the crossed upper 
fields of vision (HeNscHeN, Försrer, WILBRAND ete.) ') 
Von Monakow ’) proceeds still more in the here taken direction. 
If the dorsal division of the occipital lobe (Upper Cuneus, 0, —0,) 
incl. the dorsal part of the optie radiation is destroyed, then exclu- 
sively the dorsal layer of the lateral medullary capsule of the lateral 
geniculate body degenerates, and of this body the fronto-medial part. 
On the contrary after destruction of the ventral convolution of 
the occipital lobe (ventral lip of the calcarine fissure, the Gyrus 
lingualis, the Gyrus occipito-temporalis) it gives rise to a secondary 
degeneration of the ventral division of the geniculo-cortical radiation 
and degeneration of the ventro-lateral part (cauda) of the lateral 
geniculate body. 
The projection of the retina on the cortex could no longer be 
interpreted as simple as Henscnen had taught us. It was not limited 
only to the surroundings of the calcarine fissure and had to be 
regarded from a different point of view. 
It had to be borne in mind that in each lateral geniculate body 
there was already a first field of projection for the two homonymous 
retinal halves. Another projection, secondary to this, took place 
through the geniculo-cortical radiation, which united this body with 
the cortex. But in a particular way. 
As lone as the dorsal division of the radiation and the caput of 
this body did not show secondary change, the vision in the lower 
crossed quadrants of the fields of vision was intact. (BEEvor and 
CorLLIER). 
As long as the ventral division of the radiation and the cauda of 
the body laeked these changes, the vision in the upper crossed 
quadrants of the fields of vision could remain intact. 
The radiation from this body spreads itself however to a greater 
area of the cortex than to the surroundings of the calcarine fissure 
only. Without doubt also the upper Cuneus, O,-—0,, Le. the whole 
1) S. E. Henscuen. Pathologie des Gehirns. Upsala 1890-94 and 1903. Cf. Sur 
les centres opliques cérébranx. Rev. gén. d'Ophth. Paris 1894. Revue critique de 
la doctrine sur Je centre cortical de Ja vision Congr. int. de Médecine. Paris 1900. 
La projection de la rétine sur la partie corticale calcarine. Sem. méd. 1903. 
WirBranprt. Hemianopische Gesichtsfeldformen, Wiesbaden. 1890. 
WirBRaAnpr und Saincer. Neurologie des Auges. 3 Bde. 1900/1904. 
Férsrer. Unorientirtheit, Rindenblindheit, Andeutung von Seelenblindheit. Arch. - 
f. Opth. 1890 and WirBranprt. Doppelversorgung der Macula lutea und der Förster'sche 
Fall von doppelseitiger homonymer Hemianopsie. Beitr. zur Augenheilkunde 
(Festschr. für Förster.) 
3) Von Monaxow. Gehirnpathologie. 1905. S. 757. 
