After a series of incidents including an outright clash between a College undergraduate and a Tufts student over the right to use a book stall, Lamont officials have decided to check persons entering the library for bursar's cards.

The new policy will go into effect Monday. So far this year, the librarians have requested cards only from students borrowing books.

Staff members estimate that on a good night as many as 50 per cent of the people in the building have nothing whatsoever to do with the University. "The reading and smoking rooms are filled at night even this early in the term," Henry James, Lamont librarian, pointed out yesterday. James said the infiltration was larger than ever before, and still growing.

The clash between Tufts and Harvard students took place after the Harvard man sat down at a stall containing only two or three closed books and began to study.

A few minutes later the books' owner returned and demanded possession of the stall. The Harvard student left, only to return a moment later with library officials. In the ensuring discussion, it turned out that the books' owner was from Tufts.