1932] Poliak: Afferent Fiber Systems, Primate Cerebral Cortex 147 



In the opposite external geniculate body all nerve cells appeared 

 perfectly normal, of the normal size, of normal angular configrira- 

 tions, and well stained. 



In the ventral and ventro-lateral portion of the left pulvinar of 

 the thalamus there was an almost complete degeneration of its nerve 

 cells. This was xerj probably due to the damage of the parieto- 

 occipital cortex outside the striate area proper. The rest of the thala- 

 mus and of the midbrain appeared to be normal. 



Thus the present experiment revealed : (o) that only the external 

 geniculate body of the same side degenerated when its striate area was 

 destroyed, which means the non-existence of the hypothetical "fascicu- 

 lus corporis callosi cruciatus"; (b) that all cells of the external 

 geniculate body degenerated after the destruction of the correspond- 

 ing striate area, which means the absence of intercalated ner\T cells 

 ("Schaltzellen" of Monakow) in that body; (c) that the destruction 

 of the opercular striate area was followed by the degeneration of the 

 macular segment of the external geniculate body; and (d) that the 

 sparing of both lips and of the floor of the calcarine fissure in its 

 anterior (oral) half was followed by the sparing of the lateral and 

 medial segments of the external geniculate body and of its ventral 

 layers containing large cells, layers corresponding with the "peri- 

 pheral" portions of the hemiretinae including the monocular temporal 

 crescent. (Compare Chapter XVI.) 



Experiment V-e 



In a young Java monkey the left occipital lobe was at first luxated 

 and then with a few cuts quickly separated from the rest of the hemi- 

 sphere by means of a Gra,efe's knife. The anterior portion of the 

 calcarine fissure was removed subsequently by means of small scissors 

 and a lancet. 



Twenty-two days after the operation the animal was killed. There 

 was found no open wound of the skin in the region of operation, 

 no pus or inflammation beneath the skin or bone flap. The latter 

 fitted exactly into the defect of the skull, the rows of small trephine 

 holes having been already filled with a cartilaginous substance. The 

 dura was found adherent to the left hemisphere, but only in the por- 

 tion covering the defect. IMacroscopically and microscopically the 

 entire striate area of the left occipital lobe including its portion in the 

 anterior half of the calcarine fissure (remaining normal in the preced- 



