RECONSTRUCTION OF TARSIUS SPECTRUM 



137 



presents a typical appearance, is rather irregular in contour and rapidly 

 diminishes in size. 



The reticular formation appearing in the angle between the dorsal and 



FIG. 63. VENTRAL SURFACE OF THE GRAY MATTER OF THE BRAIN STEM, 



TARSIUS SPECTRUM. 



Key to Diagram, cochl. com.. Cochlear Complex; inferior oliv. nuc, Inferior Olivary Nucleus; mesial 



GENic, Mesial Geniculate Body; ret. form., Reticular Formation. 



ventral gray cokimns gradually increases in size and assumes the position 

 which is being vacated by the ventral gray column. The central gray matter 

 continues upward relatively unchanged until the point at which the nuclei 

 of Rolando begin to diverge one from the other. At this point the ventral 

 gray matter rather rapidly approaches the surface and becomes somewhat 

 flattened out from side to side. 



The Dorsal Medullary Nuclei 



The nucleus of Goll is the first of the medullary nuclei to appear with, of 

 course, the exception of the nucleus of Rolando. This nucleus appears a short 



