MULLENIX: EIGHTH CKANIAL NERVE. 237 



C. In Macula neglecta. 



The mode of termination in the macula neglecta is represented in 

 Figures 41-43 (Plate 6), and, as will be seen, is similar to that in the 

 sacculus and lagena. 



"b^ 



VI. Summary of Observations. 



1. Between the supporting cells and the layer of the sensory cells 

 is a region which is rich in nervous material in the form of an entangled 

 mass of fibres which extend in various directions. 



2. In this so-called nerve plexus I have not succeeded in finding a 

 case in which the neurofibrillae of one axis cylinder are in undoubted 

 continuity with those of another axis cylinder. Apparent cases of 

 anastomosis have in almost every instance, when studied with care, 

 proved to be due to an intertwining of fibres. The few cases which 

 could not with certainty be so resolved may safely be regarded as due 

 to artefact. 



3. The nerve fibres which supply the maculae and cristae are of 

 many sizes, varying from fine fibres to what have been called "giant 

 fibres." 



4. Giant fibres often expand, in the cristae, and form terminal 

 calyx-like structures, which are associated with large numbers of sense 

 cells. 



5. Large fibres, and smaller ones as well, often branch and give 

 rise to fine fibres, which end free amongst the sense cells. 



6. It is not unusual to find fine unbranched axis cylinders passing 

 from the place where they penetrate the basement membrane to the 

 region of the sense cells, amongst which they end free. 



7. It is not possible to make any general statement regarding the 

 topographical distribution of giant fibres, fine fibres, and those of 

 intermediate sizes. 



8. The terminal brush of giant fibres in the maculae takes a form 

 which is somewhat dendritic, and differs from the structure in the 

 cristae known as the "Kelchbildung." 



9. I have found no evidence of the existence of a pericellular net- 

 work of nervous material. 



10. I have found no evidence of the existence of an endocellular 

 perinuclear network of nervous material. 



11. The slight evidence which I have for the existence of intra- 

 cellular rings of nervous substance, such as Bielschowsky und Briihl 

 have described, may safely be regarded as due to artefacts. 



