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cerebral cortex. The greatest number of experiments regarding the 
localization of this center in the cerebral cortex of animals have been 
made by Munk and Ferrier. 
Ferrier considers himself justified in the belief that the visual center is 
situated in the angular gyrus. 
According to Munk the visual center is found in the occipital lobe. In 
the dog it does not, however, extend as in the monkey to the occipital pole, 
but is believed by him to be situated more anteriorly and laterally. 
Where is the visual center situated in the human cortex? Many investi- 
gators have endeavored to answer this question, but unfortunately the 
observations of these investigators have not in all cases led to the same 
results. 
Henschen concludes that the visual center is confined exclusively to that 
region of the cortex which is situated around the anterior two-thirds of the 
calearine fissure. 
According to Viallet the visual center is found in the entire mesial surface 
of the occipital cortex, and does not extend over the convex surface of the 
hemisphere. 
Seguin loeates the visual center in the cuneus only. 
Von Monakow believes that all facts necessarily speak in favor of the 
view that the visual area occupies besides the entire cortex of the occipital 
convolutions proper (cuneus, lingual lobe, gyrus descen. 01-03), also at least 
the posterior portion of the angular gyrus. 
Other investigators, as Ferrier, Gowers, Angelucci, Bianchi, Luciana, and 
many others locate the visual center on the lateral as well as medial sur- 
faces of the hemisphere. 
It is evident, from all these differing opinions, that the visual center 
has not yet been located with certainty in the human cortex. 
Structure.—The visual center in the cortex of the monkey has been 
determined beyond any doubt, and accurately located by the experiments 
of Munk. This sphere is situated in the occipital lobe behind the 
parieto-occipital fissure, or ape cleft. I have shown that anatomically 
this cortical sphere presents a typical and characteristic structure and 
can clearly be distinguished from adjoining areas. This sudden transi- 
tion in structure from the parietal to the visual cortex is very striking 
and sharply marked. It is situated at the posterior margin of the ape 
cleft, in the depth of which the parietal type is still present. 
A comparison of the cortex of the visual region with the adjoining 
cortex of the parietal region, reveals first of all the fact that the radiat- 
ing fibers in the cortex do not appear in the visual region as is so plainly 
the case in the parietal region; and consequent upon that fact the first 
layer, or layer of tangential fibers, is not as wide here as in the parietal 
region. In addition, it may be noticed that everywhere in the visual 
