198 University of Calif ornin PuHicaiions in Anatomy [Vol.2 



while in the same experiments the dorso-anterior half of the visual 

 radiation, supplying the oral half of the striate ai-ea, remained unin- 

 jured. (The origin of the respective halves of the optic radiation 

 and the loss of function was not considered in that work.) According 

 to Minkowski's investigations, the position of the various cortical 

 visual quadrants would seem to be in disagreement with those found 

 for the primates and for man. If we, however, consider the changes 

 that occurred during phylogenesis and the shifting especially of 

 the oral half of the striate area into a more dorso-posterior position — 

 probably in consequence of a more rapid development of the external 

 parietal and rolandic regions — the analogy between the oral half of 

 the striate area in lower mammals and the upper or dorsal half in 

 primates becomes more apparent. The ventral half of the striate area 

 both in the lower mammals and in primates retains, on the whole, its 

 original position. 



The striate area has been delimited by numerous investigators 

 (Brodmann, Campbell, Bolton, Mott, Smith, Mauss, Lenz, Cobb, 

 Economo-Koskinas, Putnam, Alouf, Rose, Popoff ; see also Ariens 

 Kappers and Economo) in many mammalian classes vnth. a great 

 degree of accuracy. Its relative position in the hemisphere remains 

 nearly the same through the entire mammalian scale. Owing to the 

 variable development of other regions of the hemisphere and to the 

 variable importance of the visual function in various mammals, the 

 relative position and shape of the striate area show only unessential 

 changes. Its position in primates where it is best developed due to 

 the increased importance of vision is particularly stable. ]\Iinkowski 

 (1913), showed in an experimental way the identity of the visual 

 projection cortex and of the striate area in lower mammals. In my 

 earlier experiments with cats (1927), it seemed that a narrow zone 

 immediately surrounding the striate area has also to be assigned to 

 the visual projection cortex. That zone would correspond to the 

 "limes parastriatus gigantopyramidalis " of Economo-Koskinas, but 

 the zone — if it really exists in the cortex of Felidae — must at any 

 rate be very narrow. Then, too, the difficulty of delimiting accurately 

 the striate area in preparations of the cat's brain stained by Marchi 

 has to be considered. For these reasons and considering the results of 

 the present series of experiments with monkeys, we are justified in 

 accepting an exact congruence between the striate area and the actual 

 visual projection cortex for lower mammals also, as found by 

 Minkowski. 



