350 



ANATOMY IN A NUTSHELL. 



hemisphere of the brain: the commissure magna or trabs cerebri. This struc- 

 ture is peculiar to the mammalia; it is first found in a rudimentary state in the 

 implacentals, and increases in size and complexity to the highest mammals, 

 coincidentally with a degree of other special cerebral commissures. It is also 

 called callosum. 



The corpus callosum connects the frontal, parietal, central and occipital 

 lobes. It is the great transverse commissure of the brain. It is three and 

 one-half inches long on the superior surface and two and one-half inches on the 

 inferior. It extends within one and one-fourth inches of the anterior boundary 

 <>f the brain and within two inches of the posterior boundary of the brain. It 



PLATE CLXX. 



BODY Cr LATERAL VENTRICLE. 



CHOROID PLEXUS- 



0F CAUDATE NUCLEUS 



EXTERNAL CAPSULE 



OPTIC TRACT 

 HlPPOCAMPAL FISSURE „ur.. uri„ ALBICANTIA 



A Coronal Section Through Middle Commissure of Brain. 



is convex above and concave below, thinner in the center of body than at either 

 end. Tin: posteriob end is called the splenium or ped. The anterior end 

 which is between the frontal lobes is called the genu or Knee. The rostrum is 

 the continuation of the genu and joins the lamina cinerea. On the superior 

 surface a groove extends along the median line called the raphe and on each 

 side of tlii- are the stride longitudinales or nerves of Lancisi. These 

 nerves are two distind white bands given off to the termination of the corpus 

 callosum and culled the peduncles of the corpus callosum. They pass across 

 the anterior perforated space to end in the temporal lobes, uniting with the 

 inner root of the olfactory tract. The forceps minor are fibers which go for- 



