Gustave Dax played an important role in the early history of cerebral dominance for language. He not only sent the 1836 memoir of Marc Dax, his deceased father, to Paris in 1863, but saw to it that this important document was published before Paul Broca's own article on cerebral dominance appeared later in 1865. In addition, he supported his father's contention that the left hemisphere is special for speech with 140 additional clinical cases. Gustave Dax's own unique contribution, however, has been almost completely overlooked. Although his theory lacked specificity, he preceded Meynert, Schmidt, and Wernicke in suggesting that the left temporal lobe may be especially important for speech. Copyright 1999 Academic Press.