The butterflies of San Bruno

The Mission Blue, the San Bruno Elfin, and the Callippe Silverspot are still flying just south of San Francisco, where an environmentalist drama of people vs. butterflies has been playing out.

It all started innocently enough. A company called Visitacion Associates was preparing to build 3,300 housing units on San Bruno Mountain a couple of years ago when an entomologist from the University of California, roaming the slopes, caught a Callippe Silverspot in his net. The flap of tiny wings was heard around the world -- or at least as far as Washington.

Though the Callippe Silverspot was not yet on the endangered species list, the Fish and Wildlife Service declared San Bruno Mountain a protected habitat. Then the two other rare butterflies -- already classed as endangered -- were discovered, reinforcing the argument for environmentalists. Here was a case of the $750-million butterflies, if one went by the estimate of what the development would cost.

What to do? Could the relentless bulldozer be stopped by a multicolored flutter?

A model compromise seems to have been worked out. The developer, Sherman Eubanks, did not ask why he should be held responsible for a flock of winged insects he had never heard of, just because they happened to hover above his land. Instead, he spent $800,000 to find a way to reserve an amiable environment for the butterflies while permitting human beings to coexist with them on this lovely spot overlooking San Francisco Bay.

The proposed social contract calls for planting and nurturing stands of violets and lupine on which the butterflies feed; and there will be a perpetual survey, monitoring the butterfly population. Could a San Bruno Elfin ask for more? This treatment might satisfy even a devoted lepidopterist like Winston Churchill, who stocked his garden at Chartwell with his favorite butterflies and their plants, adding a butterfly house to cater to caterpillars in the process of metamorphosis.

Whether anything short of giving the entire mountain back to the butterflies would satisfy Vladimir Nabokov is another question. The Russian exile, who some readers think wrote like a brilliantly zigzagging butterfly, confessed in his autobiography: ''From the age of seven, everything I felt in connection with a rectangle of framed sunlight was dominated by a single passion. If my first glance of the morning was for the sun, my first thought was for the butterfly it would engender.''

Did Nabokov feel so strongly because he saw the artist as a kind of butterfly , in the gorgeous superfluousness of random flight? Certainly other writers have found their symbol there, including Charles Dickens, who must have spoken from his own romantic heart when he had a character in ''Bleak House'' say: ''I only ask to be free. The butterflies are free.''

There have been antiromantics who have pointed out that butterflies are businessmen making collection routes. Far from being random, they tend to keep rigid schedules, arriving at the same patch of flowers at the same time, day after day. In Ceylon, year after year, butterflies migrate in a sort of military formation a mile wide, whizzing past at a rate of 26,000 per minute. You can't get much more organized than that.

Robert Frost, a San Francisco boy himself, perhaps thinking of the Mission Blue, wondered a little petulantly: ''Why make so much of fragmentary blue/ In here and there a bird or a butterfly''? Wasn't the sky, he asked, just as blue and a lot bigger?

But he must have known the answer. A human being has much more difficulty identifying with the sky than with a creature soaring through it, leaving the earth behind.

The Chinese philosopher Chuang Tzu never dreamed he was the sky, so far as we know. But once he dreamed he was a butterfly. He felt so happy with the situation that when he woke up he asked himself: Was he a man dreaming he was a butterfly? Or was he a butterfly, now dreaming that he was a man?

In the mood of Chuang Tzu, the parties on San Bruno have done toward butterflies as they would have butterflies do toward them. If only everybody behaved as well toward displaced persons!