THE INTERNAL CONFIGURATION OF THE CEREBRAL HEMISPHERES 



245 



strands of nerve-fibers. Two of these, placed close together on either side of 

 the median plane, are known as the medial longitudinal stria. Further lateral- 

 ward on either side, hidden within the sulcus of the corpus callosum, is a less 

 well -developed band, the lateral longitudinal stria. 



The corpus callosum is transversely striated and is composed of fibers that 

 pass from one hemisphere to the other. By dissection these may be followed 

 into the centrum semiovale, where they constitute the radiation of the corpus 



Genii of corpus callosum 

 Medial longitudinal stria 



- Hippocampal rudiment 

 ~;_-Body of corpus callosum 



Radiation of corpus callosum 



~ \--Corona radiata 



Intersection of corona ra- 



/A diata and radiation of 

 A corpus callosum 



Lateral longitudinal stria 

 Splenium of corpus callosum 



Fig. 175. Dissection of the telencephalon of the sheep to show the radiation of the corpus cal- 

 losum. Dorsal view. 



callosum and intersect those from the internal capsule in the corona radiata 

 (Figs. 174, 175). The fibers of the genu sweep forward into the frontal lobe, 

 constituting the frontal part of the radiation. Fibers from the splenium bend 

 backward toward the occipital pole, forming the occipital part of the radiation 

 or forceps major. In the human brain fibers from the body and splenium 

 of the corpus callosum sweep outward over the lateral ventricle, forming the 

 roof and lateral wall of its posterior horn and the lateral wall of its inferior 

 cornu. Here they constitute a very definite stratum called the tapetum. 



