Crowds of chanting students and local teenagers marched through Cambridge streets for nearly three hours last night. They blocked traffic on Memorial Drive for nearly 20 minutes, made two panty-raids on Radcliffe, and one of Lesley College for Women.

The size of the crowds never exceeded 800. At least one Harvard student received minor injuries, after slipping on the pavement near Radcliffe and being trampled by some of the other demonstrators. Four youths--none of them Harvard students--were arrested by Cambridge police, and at least 20 bursar's cards were taken.

Throughout the mild riot, Cambridge and University police allowed the students to roam almost at will. When the crowds congregated on Memorial Drive, University officials and police futilely attempted to keep traffic moving. In Harvard Square just before midnight. Cambridge Police Chief Daniel J. Brennan deployed about 15 men, and with the cooperation of Harvard police, made a serious effort to disperse the crowds.

Dean Monro moved through the students urging them to return to their dorms. But the crowds, although temporarily subdued, regrouped and marched through the Law School to Lesley where they were greeted by 75 cheerful girls, who encouraged the demonstrators from the balconies of their dormitories. The crowd then moved to Radcliffe, and finally, about 1 a.m., back to the Square.

This time, however, Cambridge police, their numbers augmented to about 40, had sealed off the entire Square from traffic and easily dispersed the remaining crowd of about 200 youths.

Conspicuous by their absence were the dogs employed last year by Metropolitan District Commission policemen to break up a riot of 1000 students on Memorial Drive. Only two MDC squad cars arrived while students blocked traffic, but one MDC policemen was overheard to say "in twenty minutes, the dogs will be here and eat a few of them [the demonstrators]."

Unlike last year, when students used "Save the Sycamores" as their slogan, last night's demonstration had no enduring theme. In the beginning, the marchers chanted, "Raise Cope' Pay," but this died out midway through the night.

The crowds seemed to have the most fun outside of Lesley. Some students scaled the dormitory wall, and one actually reached the fourth floor. Surprised, but happy girls hurled several dozen articles of underclothes from the balconies. After the Lesley girls were ushered back into their rooms by matrons, the demonstrators returned to the Cliffe where they taunted Moors Hall with the chant, "Lesley Gave More.