Walking through the Yard during Commencement Week, you pass countless numbers of "classmates" and assorted family in town for their twenty-fifth reunion. Workmen clatter chairs in Tercentenary Theatre and student porters wander from building to building and House to House carrying baggage, playing baby-sitter and being generally affable.

It is seldom though, that you encounter a classmate here for his fiftieth reunion. It is even rarer that you meet one of his children, for most of them are settled elsewhere with children of their own.

But walk down towards Dunster House and you will find older couples-most of whom have just turned seventy-sitting in lawn chairs, talking quietly. Here you will find little trace of the hectic cocktails-dinner party syndrome for which the twenty-fifth reunion is famous.

Indeed, classmates from the Harvard Class of 1921 made their way to registration in Dunster House yesterday for their fiftieth reunion unhurried, but happily expectant.

Old friends greeted one another in the JCR, others lounged in the welcome cool of the Dunster courtyard. It was a day of reacquaintance for the 125-odd members of the Class of 1921 who have returned to Cambridge after being away for the better part of 50 years.

And while few aspects of life at Harvard have remained the same during that interval, not all of the changes are readily apparent to the Class of '21; instead, an added touch here and there cleverly cloaks these differences.

A matron service in J entry of Dunster, for instance-provided to attend to pressing and sewing needs-is wholly foreign to undergraduates today but not so much to the classmates of '21who actually had daily maid service as students in the College.

The change is reciprocal, however. The tenor of a fiftieth reunion class is subtlety different from its graduation day elan.

"The older you get, the less you want to fight about present day issues," class secretary James A. Lowell '21 explained yesterday as he distributed registration packets, reunion schedules, room keys and shower caps to classmates and their wives.

"We're not here to argue with one another about what the University should or shouldn't be doing. We're just here to have a good time, though I'm sure we'll get into a few intense discussions," he said.

Along with reunion chairman C. Rodgers Burgin '21 and classmates Roy E. Larsen '21 and W. Houston Kenyon Jr. '21, Lowell has collected more than $520,000-representative contributions front over half of the class-to fund this 50th gathering of the class.

Of the 656 members of the original Class of 1921,293 are deceased, 343 are still living, and 20 are classified as "lost." "Lost," in University jargon, simply means that contact between an alumnus and the alumni office has, in one way or another, been terminated.

The highlight of this fiftieth reunion, according to Lowell, will come this afternoon when the classmates and their wives hold a reception for President and Mrs. Pusey in Dunster House.

At other times, informal dinners, cocktail parties and entertainment at night occupy those who are motivated to attend the plethora of functions annually scheduled for Reunion Week. Many will choose the more sedate atmosphere of small, informal gatherings.

While this fiftieth is not as large as the last two-both the Class of 1919 and the Class of 1920 had more members to begin with-it is not lacking in aplomb.

"Sure, there have been many changes at the College since we graduated." Lowell mused yesterday. "But it's still going, and we like it or else we wouldn't be here at all."

And to be sure, when it comes time for the farewell tea Thursday afternoon following Commencement and the Alumni Exercises, there will be more than one classmate who regrets departing once more-perhaps for the last time-from Cambridge and Harvard.