1932] Poliak: Afferent Fiber Systems, Primate Cerebral Cortex 57 



which resemble actual "radiated bundles" (these latter are cortico- 

 fugal as well as incoming' associational — figs. 63, 64 — and callosal fibers, 

 as other experiments in the present work show). Also no "radiated 

 fibers" remaining- normal were noticed here or were at any rate not 

 visible because of the extremely dense meshwork of degenerated fibers. 

 These latter in a considerable number approach and finally enter the 

 stripes of Baillarger, the latter being particularly well marked in the 

 central sulcus (the mentioned stripes represented by the upper semi- 

 circular layer in figs. 9 and 60 filled with black detritus). In that 

 region the inner and the outer stripe of Baillarger as well as the layer 

 between them seems to contain no other fiber elements except the 

 blackened detritas of fairly coarse and fine particles of the disinte- 

 grated myelin. A few solitary and very fine, fairly long degenerated 

 fibers of a more straight and also of an irregular oblique course, pene- 

 trate even into the upper cortical strata above the external stripe of 

 Baillarger. In our figure 60, the upper semicircular layer corresponds 

 with the lamina interstriata and probably with both the inner and the 

 outer stripe of Baillarger according to Vogt's (1919) terminology. 

 (Compare his figs. 19, 29, and 69.) The peculiarities of the intra- 

 cortical somatic sensory fibers which have just been described, namely: 

 (a) their frequently oblique ascending or horizontal course in the 

 lower strata, (&) their considerable size, (c) the well developed 

 inner and outer stripe of Baillarger containing numberless medium 

 sized and fine degenerated fibers, and {d) the presence of a few 

 degenerated fibers of a fine caliber in the upper strata above the 

 stripes of Baillarger — are all present in both walls of the sulcus cen- 

 tralis, hardly more in the posterior than in the anterior; yet of the 

 cortex of the actual bottom of the central sulcus and of the adjacent 

 cortex they are best expressed in the bottom (figs. 9, 47-49, 60). 

 The posterior wall of the central sulcus shows toward the convexity 

 of the postcentral convolution a slight gradual decrease of the num- 

 ber of the intracortical somato-sensory fibers, the stripe of Baillarger 

 also loses its distinctness in that direction (fig. 9). The anterior 

 wall of the central sulcus belonging to the precentral convolution 

 shows also a similar although hardly a more rapid decrease of the 

 number of the intracortical terminal afferent fibers. At no point, 

 however, was there noticed an abrupt cessation or disappearance of the 

 rich intracortical exogenous meshwork or of the Baillarger 's stripes. 

 It is also noteworthy that in the cortex of the fundus of the central 

 sulcus, in contradistinction to the convexities of both the pre- and post- 



