WHEN I asked Eugene what he would like me to write about him if he could choose anything in the world, he replied: ''Nothing.''
This gives me free rein to write about his kind treatment toward vegetarians, because he hasn't any. It is true that I exasperate him in restaurants when I patiently question the waitress about the possibilities, eventually resorting to my practiced look of incredulity and hint of desperation in the voice. (''You mean, even the corn chowder has meat in it?'') But I am not sure this justifies the ceaseless hamming, the foul comments, the wildlife park brochure left on my desk with the word ''camera'' altered so that I read, ''Be sure to bring your . . . knife and fork.''
When Eugene went to England, my daily mail became beefed up with meat postal cards. One had a photograph of a poultry dish, dripping with lusciousness, complete with recipe. Another bore the image of an impeccably dressed chef, carving knife and fork poised over a huge roast. The piece de resistance, however, came later from Chicago's Field Museum of Natural History. A photograph of two dinosaur skeletons, one crumpled on the floor, graced the front. The printed inscription on the back read, ''Gorgosaurus, a powerful meat-eater, towers over Lambeosaurus, a vegetarian.''
I could just as well, in writing nothing, include the smooth, uninterrupted travels with Eugene, for there are none. The success of a trip is measured by how many post offices we find. Our longtime postman always chuckled when he placed another stack of postal cards in our mailbox - to Eugene, from Eugene. George didn't need a signature to know that Gene had taken another trip; the handwriting was distinct.
When I moved to Vermont, Eugene sent me a list of 26 post offices within the surrounding counties from which he would like postmarks. Dutifully, I steered my own back road explorations around as many as possible: Hancock, Vt., to supplement his Hancock, Mich.; Wolcott, to supplement Wolcott, Ind. Each time, I smiled innocently and repeated, ''Could you cancel this one carefully, please? My brother collects postmarks, and I think this one will be special.'' Then the postmaster looked enormously flattered (especially in the smaller offices) and stamped my postal card by hand.
Eugene's conventional eating and sleeping habits can be mentioned here, also, for a list of them would contain nothing. When I was birdbanding and needed to rise around 4 o'clock each Saturday morning, I had Eugene wake me - on his way to bed. The night was his time to listen to music, usually with a raw dry onion in one hand and a bottle of Dr. Pepper in the other. I have never understood the appeal of an indulgence that admittedly wipes out all taste buds for several days.
After a visit to New Mexico, I brought back a small sack of home-dried chili peppers with which to test Gene's true tolerance. Half of one of the peppers had drawn steam from a hardened New Mexican's ears, so the other half I offered to Gene, while three of us watched. After observing a couple of tentative tastes, I detected a faint sucking in of air over the tongue and grabbed my opportunity to taunt. Someone intervened: ''You know you don't have to eat the whole thing.'' The pepper immediately landed on the table. Maintaining one's image obviously has its limits.
As does maintaining one's resolve to honor another's wishes and write of nothing. But surely I haven't overstepped my bounds with Gene's love of vegetarians, his loathing of post offices, and his legend of normal habits - for which there is nothing that can be said.
It's too bad that I'm not free to write about Eugene, though. I'd really like to tell you about his eccentricities.