The Biology Department decided yesterday to allow concentrators to use any of four upper level courses for partial fulfillment of a lower level requirement.

The department's Committee on Undergraduate Students and Studies said it would allow Biology 119, 166, 169, or 189 as substitutes for one of the four half-courses normally required in the 10-to-20 group.

"This is an ad hoc decision and will be effective this term only," Winslow R. Briggs '50, chairman of the Undergraduate Committee, said yesterday.

More than one-third of all the undergraduates concentrating in Biology had signed a petition protesting the shortage of lower-level courses.

The shortage, principally in the 10-20 series, sent overflow crowds of students to many upper-level Biology courses. Biology 166, for example, received over 200 applications for 30 available places.