The month-long gap between Harvard's 14-week winter sports season and the brief 7-week spring fling is adequately filled each year by championship tournaments. But seldom has a post-season weekend been as interesting to Boston and Harvard fans as the one just passed.

The Boston University and Cornell hockey teams, which together accounted for one half of the Crimson skaters' 12 losses this season, topped the West's best to set up the first all-East NCAA final in 18 years. It was the third showdown between the two teams: in the Arena Christmas Tournament finale they let the marbles lie with a 3-3 tie. Cornell picked up some of them with a 4-3 ECAC Tournament win last week, then took them all on the 45-minute ride back to Ithaca with a convincing 4-1 win Saturday night.

The title represents a personal triumph for the East's best recruiter, Ned Harkness, who coached the last national champion from the East, R.P.I. in 1954. It was not a particularly proud day for the Ivy League, though, unless you consider 23-year-old Canadian semi-pros who are lured to America solely for their hockey ability as representatives of the Ivy League. Cornell's style of play, epitomized in the final by all-star defenseman Harry Orr's major penalty for spearing and all-star forward Doug Ferguson's ejection from the game for fighting, is just as alien to Ivy ideals as the players' origins. Harkness wanted a national title and he got it. I hope Harvard will never permit a coach to get one in the same way.

Princeton carried Ivy hopes into the NCAA basketball tourney, but lost in the Eastern semi-finals to North Carolina. Both teams played far below par in a game that decided, in effect, who will face unbeatable UCLA in the NCAA final at Louisville next weekend. Gary Walters and Chris Thomforde, the two key Tiger performers, fouled out, and John Haarlow was sidelined by a sprained ankle. That meant that substitutes who had seen action only against Ivy tailenders were left to battle the Tar Heels in a tense overtime. The other main factor in the 78-70 U.N.C. win was foul shooting: Princeton was a miserable 10 for 21; North Carolina was 32 for 43.

Foul shooting was the only excuse for B.C.'s finding itself in the Eastern final against U.N.C. The over-rated Eagles ran into an effective freeze by Connecticut and were lucky to get past the first round. In the semi-finals they were outclassed by St. John's but squeaked by, hitting 23 of 25 second half freebies. (The Redmen from Brooklyn were so stunned by their defeat that they collapsed in the consolation game with Princeton, losing 78-58.) North Carolina had little trouble eliminating the Eagles Saturday night in a rather routine shoot-'em-up.

Far more exciting was Saturday afternoon's NIT final, in which Southern Illinois beat Marquette, 71-56. The Salukis are probably the best team east of the Mississippi and play the brand of ball that can make college basketball second to nothing for excitement. Led by Walt Frazier, as complete a ballplayer as you will find, the Southern Illinois jumping jacks exhibit the "Big D" defense that makes every pass a challenge.

Next weekend, North Carolina faces Dayton, whose credentials are no better than a 100-78 win over Harvard. UCLA will take on Houston. Sports Illustrated's predicted foursome of B.C., Kansas, Tennessee, and UCLA failed to materialized, as usual.