154 University of California Puhlications in Anatomy [^"ol. 2 



cated bj^ the uppermost stripe in figure 65 (this stripe, being also the 

 broadest, corresponds to the entire 4:-h fiber layer of Vogt [1919, fig. 

 34], the intermediate stripe being Vogt's 5-& fiber layer, the ventral 

 stripe corresponding to Vogt's 66a fiber layer). Farther up dorsally 

 within the layer 4-a of Brodmann (see Brodmann, 1909, fig. 69) 

 approximately corresponding with the lower portion of Ramon y 

 Cajal's third cell layer, only a few blackened particles and dots were 

 seen. The upper layers of the striate cortex : the first, the second, and 

 the third cell layer of Brodmann, but almost, thus, the upper portion of 

 the fourth cell layer of Brodmann (his 4-a) — , accordingly, do not con- 

 tain, in the present experiments, any disintegrated medullary fibers. 

 The fourth cell layer of the striate area, according to Brodmann 's divi- 

 sion, corresponds with the following layers of Ramon y Cajal: with 

 the lower portion of the layer of medium sized pyramidal cells (ventral 

 portion of the third cell layer of Ramon y Cajal, lamina, granularis 

 interna superficialis or the 4-a layer of Brodmann), with the layer of 

 large asteriform cells (fourth layer of Ramon y Cajal, lamina granu- 

 laris interna intermedia or the 4-6 layer of Brodmann), with the layer 

 of small asteriform cells (fifth layer of Ramon y Cajal, a little less 

 than the lamina granularis interna profunda or the 4-c layer of Brod- 

 mann), and with the uppermost portion of Ramon y Cajal's sixth 

 layer composed of small pjTamidal cells discharging an ascending 

 axis cylinder. 



According to the present investigations it is the lower portion of 

 the fourth layer of Brodmann (4-6 and 4-f) or approximately the 

 fourth and the fifth layers of Ramon y Cajal, the main granular cell 

 layer of the striate cortex and the stripe Gennari-Vicq d'Azyr, and 

 also the layers situated ventrally, Brodmann 's fifth and sixth layer, 

 Ramon y Cajal's sixth, seventh, eighth, and ninth layers, which contain 

 numerous degenerated afferent visual fibers. 



When comparing carefully the present findings regarding the rela- 

 tion of the afferent visual fibers to the various cell and fiber layei-s of 

 the striate cortex with Ramon y Cajal's description of the terminations 

 of exogenous afferent fibers in the human striate area found by means 

 of Golgi's silver impregnation (compare my fig. 65 with fig. 390, 

 p. 613, and especially with fig. 391, p. 615 in Ramon y Cajal's work, 

 1909-11, vol. 2), it becomes apparent that the uppermost layers which 

 still contain afferent fibers in the present experiments are the fourth 

 and the fifth layers and also the upper portion of the sixth layer of 

 Ramon y Cajal or approximately the 4-6 and i-c layer of Brodmann. It 



