458 AVERS. [Vol. VIII. 



its other connections. These may be called the spiral nerves 

 of the ganglion. 



The multipolar cells receive several radial fibres and unite 

 them into one body and give issue to only one central fibre 

 which may in its turn receive a collateral which passed the 

 ganglion cell or split off from the ganglion cell so as to appear 

 to arise from the centrad fibre (PI. II, Fig. 12, 13). Not all of 

 the fibres running to the periphery arise from the cell body 

 since some of them may form by the splitting of the cell 

 process even at a considerable distance from the cell. 



The whole question on both sides may be summed up in 

 these words. Both sides claim that the bipolar (and multipolar, 

 Ayers) ganglion cells have contact both with the periphery and 

 with the central nervous system. European investigators 

 claim that although the bipolar ganglion cell was originally the 

 superficial hair bearing acoustic cell it has gone below the 

 surface by elongating its body peripherally into a long nerve 

 filament which enters into relations with other superficial cells 

 which have become hair bearing acoustic cells, while I claim 

 that these investigators have overlooked the continuity of the 

 bipolar ganglion cell with the hair-cell and that in consequence 

 of this continuity we must still look upon the surface cell as 

 one-half of the primitive acoustic cell and the bipolar cell as 

 the other half which by incomplete cell division has become 

 spatially separated from its congener though still structurally 

 continuous with it. And I further claim that only on 

 this assumption can we explain the many peculiarities of 

 the finer anatomy of the auditory sense organs which their 

 theory fails to elucidate. Ontogeny alone can decide this 

 question. 



G. The Sauropsid Organ. 



The evanescent auditory organ which I have described for 

 mammalian embryos has a very interesting history with regard 

 to its innervation. At a time when the organ of Corti is still 

 very small the Sauropsid organ has reached its greatest develop- 

 ment and most of the nerves which pass into the cochlear 

 ganglion really arise from its epithelial cells. The cells having 



