58 University of California Publications in Anatomy [^oi.. 2 



central convolutions, degenerated fibers of a more or less straight 

 radiated character are entirely absent (though in the convexities too 

 they, for the most part, do not exactly correspond with the actual 

 ''radiated bundles," figs. 58, 59, 61, 62). It also ought to be mentioned 

 once more that the number of cortico-petal fibers in the bottom of the 

 sulcus centralis exceeds the number of intracortical afferent fibers 

 of the acoustic "foeal zone" in the superior temporal convolution 

 (recte in the upper wall of that convolution hidden in the Sylvian 

 fossa), and appears even somewhat larger than the number of the 

 visual afferent fibers in the striate area found in the present experi- 

 ments, which coincides with Vogt's obser^^ations. (This might be 

 partly attributable to the larger caliber of the somato-sensory fibers ; 

 compare fig. 60 with fig. 65; see also Visual System.) The described 

 narrow strip of the somato-sensory cortex along the bottom of the 

 sulcus centralis corresponds well with area 3 of Brodmann. 



An essentially similar relationship between the intracortical termi- 

 nations of the thalamic fibers and cortical structures, although with 

 some differences, was found in the cortex of the convexity of the post- 

 central convolution corresponding with areas 1 and 2 of Brodmann. 

 (Compare figs. 58, 59 which correspond with the posterior lip of the 

 central sulcus in figs. 9, 48.) Here the number of exogenous intra- 

 cortical, moderately coarse, and coarse thalamic fibers (black lines and 

 dots in the corresponding figures), is already considerably smaller 

 than in the cortex of the bottom of the sulcus centralis. Also a few 

 of them take a course more or less similar to that of the "radiated 

 bundles," the latter remaining otherwise perfectly normal (yellow 

 lines in accompanying figures). The majority of the somato-sensory 

 terminal fibers here too, however, have an oblique ascending course 

 toward the middle strata quite distinct from the actual "radiated 

 bundles. ' ' Numerous intracortical fibers, and not only those near the 

 white subcortical substance, but also those close beneath the inner 

 stripe of Baillarger take a more or less horizontal course. These fibers 

 which often traverse long distances, can be seen especially in sections 

 whose planes lie parallel to the long axis of the postcentral convolution. 

 They resemble similar subcortical afferent somato-sensory fibers imme- 

 diately beneath the cortex. In areas described here, fewer degenerated 

 somato-sensory fibers reach the inner stripe of Baillarger, from where 

 they often proceed for a short distance in a horizontal direction. (Com- 

 pare Ramon y Cajal, 1909-11, vol. 2, p. 641, fig. 406, with my figs. 58, 

 59 ; in my figures the inner stripe of Baillarger is seen in the upper 



