98 University of California Publications in Anatomy [^'o^.- 2 



Domena. An equal distance could be supposed for all spironeura (in 

 our scheme fig. 11 the a system) — and there are some reasons to make 

 such a supposition (see my paper, 1927) — which they have to pass 

 from the group of hair cells where they terminate and where they 

 receive impulses (for instance, for hair cell groups corresponding with 

 the orthoneural groups A^, Ao and so forth) along the outer rows of 

 the hair cells to the point where they turn inward toward the spiral 

 ganglion (for instance the spiro neural group a-^^ near the hair cell 

 group corresponding with orthoneural group A^) . Further by sup- 

 posing that their respective nerve cells belong to another segment of 

 the spiral ganglion than do the nerve cells which send orthoneural 

 fibers to the same group of hair cells, one would find a constant rela- 

 tion between the spironeural and orthoneural apparatus throughout 

 the cochlea (^1^ to Oi, Ao to an, A, to Om and so forth). If we now 

 take the next step and accept the "spatial" organization of the entire 

 central auditorj^ path up to the auditory projection cortex, we would 

 find each of the groups of hair cells maintaining a constant relation 

 to two different groups of cortical cells (for instance hair cells A^ to 

 both cortical cell groups X^ and Xi, A, to Xo and Xn and so forth). 

 According to that hypothesis there would exist from the cochlea 

 to the cortex two different and yet intimately interrelated conductor 

 systems: one corresponding to the orthoneural system (A) and the 

 other to that of the spironeura (a), with constant relations between 

 both. The result of such a double conductor system would be that 

 whenever a single, definite group of hair cells is stimulated, that 

 stimulus invariably finds its way centralward by two different groups 

 of neurons (for instance by fibers A-^, and ai, by Ao and an and so 

 forth) and would always reach two different groups of cortical cells 

 (for instance, X^ and Xi, Xo and Xn and so forth).- Considering 

 the small number of "spiral fibers" in comparison with the "direct 

 fibers" one finds that the role of the spironeural apparatus (a-system) 

 appears as complementary or accessory in respect to the main 

 orthoneural apparatus (A-system) which transmits the main part 

 of the nervous current underlying audition. This means that when 

 a single group of hair cells, for instance those related to the ortho- 

 neural group of conductors A-^, are stimulated, it will be the 

 cortical group of cells Xy which will receive the main stimulus, while 

 the cortical group of cells Xi will get only a trace of such a stimulus 

 (by the way of a-i spironeura). The latter stimulus would in itself 



Compare Goebel, p. 114. 



