The pictures that accompany this editorial are a small selection from an archive of Press photographs showing students in every local school attending classes held in closets, hallways, lunchrooms, dressing rooms, medical offices, a vault, and bathrooms.

We've published photographs like these for nearly 20 years. Some of the students who endured these conditions have graduated from college by now. Some who didn't go to college might have, if the setting in which they were taught had not so clearly proclaimed to them that their city had so little respect for children and for learning.

Whenever we publish these pictures, principals wince. "You're giving the schools a black eye," they say. But how are citizens to be moved to change these conditions, if they aren't kept vividly aware of them?

Last week, the Schools Chancellor saw a picture similar to these. Like the principals, he winced. He attacked mayoral candidate Ruth Messinger for an advertisement that showed a class being held in a bathroom and blamed Mayor Rudolph Giuliani for failing the city's children.

Ms. Messinger's commercial was a dramatization, shot in a private school, since the public schools cannot be used for partisan political purposes. Dr. Crew characterized her message as an attack on the school system and on its children.

The Chancellor seemed particularly upset by the urinals in Ms. Messinger's ad.

When have we heard the Chancellor speak so forcefully about the appalling conditions in which thousands of students spend their school day as he spoke about Ms. Messinger's ad?

Our pictures of the bathrooms where the children of Riverdale and Kingsbridge have gone to class show no urinals. Does that make them fit places for learning?

Whatever Rudy Crew may say, children are going to class in bathrooms in this city. They are going to class in bathrooms in Riverdale. But if they weren't, we would still not be educating them in a fit setting for learning.

At PS 310, prefab huts have sat in the school yard for so long that today's parents probably don't know their school once had a playground. Those huts have no urinals, but are they the classrooms our children deserve?

At the David A. Stein Riverdale School, MS 141, and at other local schools, new walls have been built to divide many classrooms in half. The students, and even some young teachers, may not know that an earlier generation was better accommodated. Does that make these cramped rooms the classrooms our children deserve?

At PS 95, some students are shunted to an annex; at John F. Kennedy High School, they have begun attending classes in prefab modular units; at PS 7, a projection booth has been pressed into service. And in every building there are too many students in classes that are too large to permit teachers to offer enough individual attention to their charges.

At last week's meeting of Community School Board 10 the district's UFT representative, Marsha Silberman, chastised the board and Superintendent Irma Zardoya for failing to speak out forcefully about overcrowding. She is right.

District 10 is the city's largest school district. Few districts have been overcrowded longer. It continues to grow each year. This year more than 900 new students will attend its schools, but it has added only 400 seats. The best the Board of Ed can promise is some 4,200 seats over the next two years in leased buildings and more huts. Is that what our children deserve?

Mayor Giuliani turned an indifferent eye to the school system until this year, when polls told him that his record on education was vulnerable. In this election year, he has turned on the money spigot. But he has shown none of the understanding and none of the urgency that characterized his attack on crime.

The crisis of New York's public schools is as deep and its solution as vital as calming New Yorkers' fear of crime. Our city cannot be a beacon for immigrants or a haven for the middle class citizens of communities like Riverdale without first-rate public schools.

The issue is not where a commercial was shot but where teachers are going to teach and kids are going to learn. The issue is when the children starting kindergarten today will have the classrooms they deserve.