DISSECTION OF THE HEAD AND NECK 



339 



(d) Beak of corpus callosum (rostrum corporis callosi). 



(da) Rostral lamina (lamina rostralis). 



(e) Transverse striae (striae transversae) . 



(f) Medial longitudinal stria (stria longitudinalis medialis). 



(g) Lateral longitudinal stria (stria longitudinalis lateralis). 



(h) Fasciola cinerea (fasciola cinerea) ("ash-like little bandage"). 



Lateral Ventricle (Ventriculus lateralis). 



Make a sagittal incision through corpus callosum one centi- 

 metre from sagittal median plane; the part of the corpus cal- 

 losum lateral from the incision is to be reflected lateral ward and 

 removed; leave the part of the corpus callosum medial from 

 the incision in place. Note the relation of the splenium corporis 



FIG. 152. 



Cornu anterius 



Foramen interventriculare [Monroi] 

 Ventriculus tertius 



..Cornu inferius 

 Aquaeductus cerebri [SylviiJ 



Ventriculus quartus 

 .Cornu poster! us 



Cast of the ventricles. (After Welcker.) (From Poirier et Charpy, Traite d'Anat. hum., Paris, 1901, 



2ed., t. iii., 1, p. 365, Fig. 260.) 



callosi to the pars occipitalis of the radiatio corporis callosi, or 

 forceps major; leave the latter in place. 



The central part and anterior cornu of the lateral ventricle 

 are now exposed. Make a cut backward and lateralward through 

 the white matter which forms the roof of the posterior horn and 

 excise enough of this roof to permit of thorough inspection of 

 the cavity. To open the inferior horn, place the tip of the knife 

 in the central part of the ventricle at the entrance to the inferior 

 horn and make a cut downward and forward through the outer 

 part of the temporal lobe towards the polus temporalis, following 

 the course of the inferior horn, which runs nearly parallel to 

 the sulcus temporalis superior. Now remove the part of the 



