Mary J. Cox will direct Radcliffe's Office of Development and Alumnae Affairs beginning Oct. 1, President Horner announced yesterday.

Cox replaces Hope W. Wigglesworth '48, who resigned last month to become director of development for the Affiliated Hospitals Center in Boston. Cox, a former assistant to Horner, serves as vice president and editorial director of a Cambridge-based editorial consulting firm.

As director of the development office Cox will oversee the school's effort to reach its Century Fund Drive goals: $3.5 million in program grants and $10 million in endowment and capital improvement funds for construction and renovation of Radcliffe facilities.

Cox said yesterday she does not yet have specific plans for the office.

Horner assigned a search committee to find a replacement for Wigglesworth early last spring. A minimum of three to five years experience in administration--preferably in fundraising--was one of the committee's criteria in the selection process. The committee recommended Cox and a few others to Horner last August.

She's Wonderful

"We think she's a wonderfully qualified person," Phyllis Stein, chairman of the search committee and director of Radcliffe Alumnae Career Services, said yesterday.

In addition to the director's duties as head of the fund drive, Cox will also be responsible for preparing the $16 million budget, working with the board of trustees on corporation fiscal concerns and coordinating alumnae fundraising efforts.