White Matter
Human brain right dissected lateral view, showing grey matter (the darker outer parts), and white matter (the inner and prominently whiter parts).
By John A Beal, PhD
Dep't. of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center Shreveport - http://www.healcentral.org/healapp/showMetadata?metadataId=40566 (Internet Archive of file description page), CC BY 2.5, Link
All the cables and connections that go from one part of the brain to another part.
- Those fiberous things are bundles of axons connecting remote parts of the brain to each other.