Final answer:
The cerebral hemispheres in mammals are connected by the corpus callosum, a large bundle of axons that enables communication between the hemispheres.
Step-by-step explanation:
The mammalian cerebral hemispheres are connected by a mass of white matter called the corpus callosum. The cerebral cortex is the outermost part of the brain, consisting of two hemispheres separated by the longitudinal fissure. The corpus callosum, a thick bundle of axons comprised of about 200 million axons, serves as the major pathway for communication between the two cerebral hemispheres. It allows for messages and information to be transferred between the hemispheres, facilitating integrated brain functions.