The corpus callosum is a neopallial commissure. In inferior vertebrate
s, the pallial commissures are essentially represented by the anterior
commissure. The corpus callosum appears in mammals only. Eutherians a
lone have a corpus callosum, the other mammals have an anterior commis
sure and hipocampal commissure. In humans, the different portions of t
he corps callosum are described on a median sagittal slice : rostrum,
genu, body, isthmus, splenium. Klingler method allows to dissect fiber
s of each of these portions and their relationship with the corona rad
iata and optic radiations. These latter are separated from the ventric
ular ependyme by callosal radiations. Finally, each part of the corpus
callosum participates in lateral ventricle wall formation.