300 University of California Publications in Anatomy [^'t 



Ssm SsC 



Fig. 95, Experiment XV. In this experiment the cortex around the dorsal 

 extremity of the simian sulcus was damaged (Brodmann's fields 18, 19). From 

 the lesion two distinctive fiber systems enter the sagittal layers of the parietal 

 lobe: (1) a thin well circumscribed bundle in the tapeteum (Tap) which enters 

 the splenium of the corpus callosum and occupies in the opposite hemisphere 

 exactly the same position in the tapetum, (2) another group of fibers which enter 

 the external sagittal layer (Sd) and to a slight extent the internal sagittal layer 

 (Ssm) and finally pass through the pulvinar of the thalamus by forming the 

 brachium of the superior eolliculus to reach the roof of the midbrain. (Compare 

 next figure.) In other experiments it was found that the internal sagittal layer 

 is composed of efferent fibers. (Compare figs. 68, 69.) 



