53 



VII I , and X nerves. 



The structure of the tubei-culuir, acusticurr, embraces a medio- 

 central core in which bundles of nerve-fibres predominate; and 

 an outer ir.vesting cap, the cerebellar crest ( Fitj. ?,cb.cr. ) . 

 The latter, in its outer levels, is morphologically continu- 

 ous with the molecular layer of the cerebellum, so that the 

 term TiOleoular lauep is very properly applied here. The neu- 

 rones of the tuberculum acusticum lie chiefly in the cerebel- 

 lar crest, with just a few, also, in the central core. Three 

 varieties are to be distinguished: Purkinje neurones, granular 

 neurones, and molecular neurones. I have so designated them 

 because each is the equivalent in every way of the element 

 bearing such a name from the cerebellujr. 



a. Molecular and Granular Heurones. — The molecular and 

 the granular neurones do not call for any extended description 

 here, since they are directly comparable with the cerebellar 

 representatives described at length in Section V. 



The molecular neurones are the most numerous of the three 

 varieties peculiar to the tuberculum acusticum. They are found 

 scattered throughout the molecular layer, most abundantly in 

 the deeper levels. Bach has the characteristically small cell- 

 body with slender dendrites radiating from it. 



The granular neurones are far less numerous. They lie 

 just within the base of the molecular layer, but there are 

 not enough of them to form a distinct zone. Stained with 



