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AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



fibres which convey the impulses arriving over the auditory nerve (the coch- 

 lear branch of* the eighth). Finally the fourth area is seen (area for "body- 



Fig. 109.— The colored portion about the cuneus, especially that more deeply colored about the cal- 

 carine fissure, shows the visual area as seen from the mesial surface. The portion comprising the deeply 

 colored tipof the hippocampal gyrus, the dorsal portion of the hippocampal gyrus, and the edge of the 

 gyrus fornicatus through its entire extent, marks the olfactory area. The remaining portion, occupying 

 the paracentral gyrus and the mesial aspect of the first frontal gyrus, marks the mesial extension of 

 the body-sense area. The uncolored portions of the cortex form the association centres of Flechsig. F, pes ; 

 HS, crura; Z, pineal body ; 1, corpus albicans ; 2, chiasma ; S, anterior commissure ; 4, quadrigemina ; 

 5, callosum ; 6, fornix; 7, septum lucidum (from Flechsig). 



Fig. no.— The colored portion at the tip of the occipital lobe represents the postero-lateral extension 

 ofthe visual area. 'I he colored portion about the central fissure and the neighboring parts of the frontal 

 lobe represents the lateral extension ofthe body-sense area. The colored portion about the caudal end of 

 the first temporal gyrus, and extending over the transverse gyri within the sylvian fissure, represents the 

 auditory area. In all three areas the portions most deeply colored represent theareas where the projec- 

 tion-fibres are most abundant. The uncolored portions of the cortes form the association centres of Flechsig 

 i from Flechsig). 



sense"), which is most richly supplied with projection-fibres about the central 

 fissure, in the two central gyri — but also extends forward on the lateral sur- 



