524 ANIMAL PHYSIOLOGY. 
About the same time another experimenter (Munk) had 
been attempting to map out the region of the cortex concerned 
in vision. Asa result of removal of different portions of the 
occipital lobe in dogs, he had concluded that a portion of this 
lobe constituted the cortical visual center, and, further, that 
the blindness resulting from such operations as are now under 
consideration was either “absolute” or “ psychical”; by which 
was meant, in the first instance, an inability to bring the images 
of the retina into consciousness, and, in the second, inability to 
interpret visual sensations intelligently, the one or the other 
result being dependent on the part of the limited visual center 
that was removed. This may be regarded as perhaps the most 
extreme form of sensory localization yet taught. 
Goltz, as a result of his latest experiments, not only denies 
that operations on the occipital lobe are peculiar in producing 
visual disturbances, but points out that these lead to sensory 
defects overlooked by Munk. This observer (Goltz), as a result 
of comparing a dog, with both anterior cerebral lobes removed, 
with others from which were removed, in the one case, the 
right, and in the other the left corresponding parts (anterior 
cerebral lobes), since he finds the dog with both removed ina 
worse condition than would be represented by the joint result 
of the addition of the imperfections of the other two, concludes 
that one cerebral lobe may, to a certain extent, take up the 
functions of another. In other words, he admits localization 
but only of the roughest kind. 
A view advanced by Schiff deserves probably more consid- 
eration than it has received, viz., that motor areas are so related 
to tactile sensations arising in different parts of the body that 
when the former are stimulated the resulting movements are 
really reflex—i. e., the stimulation of the cortex replaces the 
afferent sensory impulses, which usually are associated with 
the movements in question. 
In the mean time it has been found that in many cases it 
was possible to locate the site of a brain-lesion (tumor, etc.) by 
the symptoms, chiefly motor, of the patient; and brain-surgery 
has in consequence entered upon a new era of development. 
Tumors thus localized have been removed successfully, and the 
patients restored to health. As a result of the various kinds of 
observations and discussions on this subject of late years, the 
localizationists are willing to admit that the areas of the cortex 
can not be marked off mathematically—that, in fact, they 
“overlan.” This is in itself an imvortant concession. Again, 
