MULLENIX: EIGHTH CRANIAL NERVE. 219 



embryological side in an investigation of the development of the peri- 

 pheral nervous system. By a study of embryos and young of the mouse 

 they were led to the conclusion that the fibres of the eighth nerve grow 

 out of the cells of the spiral ganglion toward the sensory epithelium. 

 x\t the same time "the impulse is given for building a fibrillar network 

 within the sense cells, from the contained granular substance." They 

 were led to regard the peripheral nervous system as a fibrillar mechan- 

 ism which is directly united with the cerebrospinal and sympathetic 

 ganglion cells. They were not able to satisfy themselves of the exist- 

 ence of free fibrillae, either intracellular or extracellular. In accord 

 with von Lenhossek's view of the sense cells as short nerve cells without 

 processes, they regarded the sense cells as wholly like ganglion cells, 

 being organically united with the terminal fibres of the eighth nerve. 

 They concluded that the results of their investigation must be regarded 

 as furnishing further evidence against the neurone theory and in favor 

 of the fibrillar theory. 



Kolmer (:07) contributed further to the subject in a paper based on 

 conditions found in domestic mammals. The method employed was 

 the reduction process of Ramon y Cajal. He stated that fibrillae of a 

 given axis cylinder are frequently in union with those of several sense 

 cells, and that the fibrillae of a given sense cell can be shown to be in 

 connection with fibrillae of different axis cylinders. Kolmer, unlike 

 Ramon y Cajal, found both the giant fibres and fine fibres in the 

 maculae, as well as in the cristae. He was not able to confirm Ramon y 

 Cajal's distinction as to topographic distribution, inasmuch as he 

 found both kinds of fibres in all parts of the cristae. He states (pp. 

 757-758) that the union between sense cell and axis cylinder appears 

 to result from a growing together or interlacing of fibrillae which 

 originate in the sense cell and fibrillae from the axis cylinder. A 

 growth of fibrillae from the axis cylinder into the sense cell appears to 

 him to be excluded, as does an outgrowing of fibrillae from sense cell 

 to axis cylinder. He is inclined to regard the sense cells as peripheral 

 nerve cells, and to believe that fusion between their fibrillae and those 

 of the axis cylinder has taken place secondarily. 



Finally, the most recent publication upon this subject that has come 

 to my attention is that of Bielschow^sky und Briihl (:07). The 

 formaldehyde method of reduction of silver oxide was applied by 

 these investigators to the ear of the guinea pig and of human embryos. 

 In agreement with Kolmer and other investigators, they affirm that 

 true anastomosis between neighboring fibres is not rare in the nerve 

 plexus underlying the zone of sense cells. From this plexus some fibres 



