Corpus Callosum

Thought maybe I better explain what a corpus callosum is in the first place. I have c & p'ed from Wikipedia. http://en.wikipedia.org/wiki/Corpus_callosum

The corpus callosum is the largest white matter structure in the mammalian brain. It consists mostly of contralateral axon projections. It appears as a wide, flat region just ventral to (below) the cortex. It is missing in monotremes and marsupials. It is made up of 200-250 million nerve fibers.
The corpus callosum connects the left and right cerebral hemispheres. Most (but certainly not all) communication between regions in different halves of the brain are carried over the corpus callosum. The posterior portion of the corpus callosum is called the splenium; the anterior is called the genu (or "knee"); between the two is the body. The most anterior part is the rostrum. Agenesis of the corpus callosum is a complete or partial absence of the corpus callosum in humans.