ATLAS OF NERVE CELLS 



Plate XXIV. shows a portion of the deep white layer of the corpus quadrigeminum. It 

 demonstrates the inextricable interlacing mass of nerve fibres which appear to be passing in 

 every direction. Among these fibres, numerous cells are seen of varying size. The majority 

 are triangular with a long apical process pointing outward and downward. These cells have 

 numerous dendrites which give off branches. The direction of their neuraxons is downward 

 and inward to the III. nerve nucleus. They are smaller than those in Plate XXIII., 

 being from 20 to 30 /u, in size. Through the mass of fibres there appear to be numberless 

 fine neuraxons with collaterals, and many of them seem to have free ends. Tartuferi 1 and 

 Amaldi * have studied the corpora quadrigemina by the Golgi method, but I have not had 

 access to their writings. 



The corpus quadrigeminum posterior contains cells and fibres quite similar in appearance to 

 those shown in Plates XXIII. and XXIV. It has a relation to the auditory apparatus quite 

 homologous to that which the anterior body has to the visual apparatus. The fillet conveys 

 the auditory impulses to the corpus quadrigeminum posterior and to the corpus geniculatum 

 internum, and to the posterior nucleus of the thalamus, and from these centres a second tract 

 conveys them outward to the temporal region of the cortex. Von Monakow has shown that 

 in both of these tracts fibres pass in both directions as in the visual tracts. 



1 F. Tartuferi, Sull' anatomia minuta d. eminenze bigemine anterior! dell 1 uomo, Archivio ital. p. 1. malettie nervose; 1885. 

 * P. Amaldi, Rivista sperimentale de Freniatria; 1892. 



