The two hemispheres communicate via dense bundles of nerve fibers called the corpus callosum.
As additional features of the subclass may be mentioned the absence of a corpus callosum connecting the right and left hemispheres of the brain,' and of a fossa in the septum between the two auricles of the heart.
In some cases (as in rat-kangaroos) this tooth retains its place and function until the animal has nearly, if not quite, 1 The presence or absence of the corpus callosum has been much disputed; the latest researches, however, indicate its absence.
In particular, the corpus callosum, the part of the brain that joins the left and right sides, may be abnormally small or even missing.
The participants all had a smaller corpus callosum than average person.