Several hundred mourners attended the funeral of Lawrence Davis Senior, the former president of Arkansas A-M-and-N College and the first chancellor of the school when it became the University of Arkansas at Pine Bluff. Davis, nicknamed Prexy by students, was buried yesterday. He died Saturday at the age of 89. The Reverend Beecher Hicks Junior of Washington, D-C, an Arkansas A-M-and-N graduate, delivered the eulogy. He said Davis set out to build an institution despite a social structure that believed black children didn`t need an education.