What connects the two hemispheres of the cerebrum?
The answer is corpus callosum .
Cerebrum forms the major part of the brain and longitudinally divided into left and right cerebral hemispheres by a deep cleft called longitudinal fissure.
The two hemispheres are internally connected by transverse, wide and flat bundle of myelinated fibres beneath the cortex, called corpus collusum. It brings about coordination between two hemispheres of the cerebrum.
The yellow band in the diagram shows location of corpus callosum between cerebral hemispheres (only one hemisphere shown).