This little book is a review of and contribution to the subject of language and its relationship to cerebral dominance. In general it emphasizes that in right-handed people language function is nearly regularly and fairly strictly localized to the left hemisphere. In left-handed and clearly ambidextrous people there is still a tendency for language to be localized in the left hemisphere, but its localization is not as complete, and various language functions may escape in injury to one hemisphere. Recovery tends to be more complete following acute lesions of the left hemisphere in predominantly left-handed individuals.