State schools up and down the country were reinstating or introducing such symbols as they sought a distinct identity, he told private school heads.
"Schools recognise that a rag-tag roll call is not good enough if pupils are to come to school to learn," Mr Bell said at the annual Brighton College conference on independent education (see story above).
"How did we allow ourselves to be persuaded that jettisoning all of these features was ever going to be in the interests of the pupils we served?" he asked, knowing full well that private schools never had.
Mr Bell made clear that a much-trailed crackdown on private schools by the Office for Standards in Education applied only to a minority of the 1,100 small schools not covered by the Independent Schools Council. One in seven of these was poorly managed, he said.
From this September, inspectors will have powers to mount a full inspection before an independent school opens and will be required to inspect again in its first full year of operation.
Alan Smithers, professor of education at Liverpool University, warned the conference that private schools would struggle to keep their places at the top of the A-level league table.
This was partly because so many state pupils were now achieving A grades and partly because vocational qualifications were being given generous point scores. A merit or distinction in leisure and tourism GNVQ now counted for twice as much as an A-grade in physics A-level.
But he cautioned private schools against a wholesale move to the International Baccalaureate, arguing this could make it easier to discriminate against their pupils in university admissions.
Private school heads seemed poised to abandon their boycott of applications to Bristol University and are also set to shift funds away from scholarships for clever pupils towards bursaries for needy ones.
Already four schools - Eton, St Paul's boys', King's College Wimbledon and Dulwich College - have agreed to reduce the value of their top academic and music scholarships from September 2004.