It's just another day in the life of a University president," President Bok said late yesterday afternoon as he hurried down Mass Ave followed by a crowd of 75 students demanding that he speak to them about Harvard's investments in corporation operating in South Africa.

Fifteen minutes earlier, Bok emerged from a meeting in University Hall. He tried to cross the Yard to his office in Massachusetts Hall, only to be blocked by a group of demonstrators.

As plain-clothes and uniformed Harvard police attempted to clear a path for Bok, students tried to stop him, sitting down in front of him and locking arms outside the guarded entrance to Mass Hall.

Despite efforts by Harvard police to clear a path, Bok, Dean Fox, Dean Rosovsky and Archie C. Epps III, dean of students, failed in their attempt to enter Mass Hall.

The group of administrators then headed out Johnston Gate into Harvard Square, still surrounded by a large group of chanting students who demanded that Bok speak with them.

Shoppers in Harvard Square looked on as Bok stood among the shouting students. A Harvard police car headed onto Mass Ave against oncoming traffic. As the car U-turned and stopped, four plain-clothesmen helped Bok move through the crowd. Despite students' protests, Bok, aided by the policemen, entered the car.

About a dozen students then threw themselves in front of the police car, some lying down on the pavement on Mass Ave as the car inched forward.

The small group abandoned its efforts to stop Bok's departure when the car continued to move. With lights flashing and sirens sounding, the car pulled quickly up Mass Ave.