Truman Capote had this fascination with snakes. He once wrote:

Question: Suppose you were drowning. What images, in the classic tradition, do you envision rolling across your mind?

Answer: A hot Alabama day in, oh, 1932, so I must be eight, and I am in a vegetable garden humming with bees and heat waves, and I am picking and putting into a basket turnips and slushy scarlet tomatoes. Birds, bird-music, leaf light, the stringent taste of raw turnip on my tongue: pleasure everlasting, hallelujah. Not far away a snake, a cotton mouth moccasin, writhes, ripples across the water; I'm not afraid of it.

. . . And at midnight when the churchbell chimes I'm eight. Once more, the creek. The taste of raw turnip on my tongue, the flow of summer water embracing my nakedness. And there, just there, swiveling, tangoing on the sundabbled surface, the exquisitely limber and lethal cotton mouth moccasin. But I'm not afraid; am I?

Only a few of his friends knew about Capote's interest in snakes; but, as anyone who sees the exhibition of Capote portraits, ephemera and collage boxes in the Gotham Book Mart (41 W. 47th St.) will discover, the late author made a fetish out of snakes.

He started what he called "my secret project" in 1979. On a trip to Alabama he purchased a number of snake-bite kits. He pasted bits of paper and photographs to the kits, in the manner of Joseph Cornell. Soon his assembly grew to number 25.

He later showed the boxes to Gotham Book Mart's Andreas Brown and was persuaded to exhibit them in the famous bookstore's second-floor gallery. The show had been scheduled before he died last year. By the end of last week, the boxes had nearly all been sold, primarily to friends of Capote: socialite C.Z. Guest, Lester Persky and Joanne Carson.

Capote drew upon other themes for his small Plexiglas boxes: a somber tribute to Marilyn Monroe, with hints of death and despair, including the well-known photograph of her dancing with Capote. Yet another has pictures of San Quentin death-row inmates. Writers, corn and tomato, raccoons, leopards, lizards, candy, Alabama and Kabuki dancers are also featured.

Most of the boxes, though, are built around the snake; there is also the portrait by Horst B. Horst of the author and his snake, a beaded folk-art snake, a carved jointed wood snake, a snake-bite kit, a stuffed snake, another carved snake.

The show runs through May 10.