IN SOME SENSE, conventions really are mastodons, as Haynes Johnson observed in this paper yesterday, or something like them -- great, ungainly, crashing-around beasts. We leave to you their exact biological description, insisting only on two attributes: they have teeny, tiny memories and even tinier senses of shame (some political zoologists say they have neither).

We are moved to this scientific observation by the wonderful overnight change from Monday to Tuesday that we, along with the rest of the world, were lucky enough to observe at the Democratic gathering in New York. On Tuesday night a deal was cut between the Kennedy and Carter forces on procedures for voting on the contested economic platform planks. It was decided in advance, backstage and on the phone, which ones would be won and which lost by the administration forces and that there would be no bothersome and contentious and protracted roll call tests of the outcome. And there, in all his glory, Speaker O'Neill stood and did the necessary listening and gavel-work, miraculously hearing the thing -- the ayes and the nays -- a little differently from some of the rest of us, but in accord with the deal that had been cut.

And it was done.

Don't get us wrong: we think, as you will see elsewhere in this space, that economic judgements are not made best in the setting of a political convention but that political judgements, a la that reached by the compromisers and enforced by Speaker O'Neill, are precisely what a convention is there for, as this arrangement demonstrated.

What gets us is something else. Say, isn't this the crowd whose leaders only the night before it calmly accepted this deal, a deal that ran over a whole lot of audible free expression, had been filling the air with pieties about the delegates' inalienable right to freedom of choice and one-person-one-vote and the rest? Wasn't this the bunch that was talking about Jean-Jacques Rousseau and John Quincy Adams and the Founders and the Farmers and other greats in the tradition of democracy? Didn't we hear a whole lot of protestation in connection with the "open convention" issue that each of these delegates would feel plain dirty and misused if he or she could not vote and have that vote counted according to free will and conscience?

Oh, well. The thing about the mastodon is that although the beast is supposed to have looked vaguely like its most famous descendant, it is different. The mastodan never remembers.