The Class of 1971 came into being at precisely 12:01 this morning when the Admissions Committee mailed letters of acceptance to 1360 of a record 7150 applicants.

According to Committee projections, 85 per cent -- about 1150 -- of those accepted will decide to enter Harvard next fall.

It is possible, however, that there will be a substantial jump in the number of acceptances this year. "John Monro's move will appeal to a lot of young people; it might increase our yield significantly," David K. Smith '58, director of Admissions, said yesterday.

If there are fewer than 1200 acceptances by May 1, the College will admit a number of the 200 to 250 applicants now on the waiting list in order to fill out the freshman class.

The new class will be very similar in composition to the class of 1970. All 50 states as well as 20 foreign countries will be represented, Those accepted include 110 Merit Scholars -- exactly the same number as last year.

Slums and Suburbs

The median College Board Scores for the class are 680 in verbal and 710 in math -- a level which has varied little over the past few years. "The scores have remained constant at least partly because of our efforts to get students from rural areas and urban slums; they don't score as well as those from suburbia," Smith said.

The number of freshmen receiving scholarships from Harvard will probably increase from this year's 420. Five hundred and fifty of those accepted for the class of 1971 have been offered Harvard College Scholarships, worth a total of $925,000. The Committee expects 84 per cent -- approximately 460 -- to accept the aid. Smith attributed this rise to the increased number of highly qualified applicants from low income families.

The proportion of public school students in the class will continue its one per cent yearly growth, Smith said. He explained that there had been more applications from public school students and that the increase was not the result of any admissions quota. In recent years approximately 58 per cent of the freshman class have been public school graduates.

The private school sending the most students to Harvard next year will be Exeter. The Boston Latin School led all public schools in number of candidates accepted.