Legs. And clingy skirts that swish over them just so, and the rustle of nylons on the legs as they cross and uncross, legs belonging to one obsession after another in the life of Bertrand Morane: women.

It is such a nice, conventional obsession these post-Steinam days - almost nostalgic. And Bertrand, who appears to be more conventional than kinky, is the man in Francois Truffaut's "The Man Who Loved Women," a film devoted to one man's chase after a parade of women.

There are assorted droll, if sometimes unbelievable, interludes between Bertrand and the women he fancies, and he goes that extra kilometer to find out who the legs belong to. But after a half dozen or so close encounters of the third kind - especially after you learn about his mother who kept a scrapbook of her lovers - the chase gets tiresome. It doesn't take a Freud to figure out why Bertrand plays love by the numbers.

Truffaut has made so many interesting films, films depicting curious adult relationship ("Two Englishwomen," about a man in love with two sisters), about making films ("Day For Night") and about the pain of growing up ("400 Blows" and "Small Change"). He seems most sensitive in films about real children, perhaps because he had such a lonely childhood himself, spending a brief period in a reformatory. But in Bertrand, a spoiled, manchild over 40, Truffautfails to evoke the same sympathies.

Bertrand, aptly played by Charles Denner, toward the end begins to develop a deeped relationship with his editor than he has enjoyed with other women, and there is a hint at the passing of adolescense. But, alas, as the aging playboy leaps over a traffic island in one final chase after a pair of legs and a red Porsche runs him down, Truffaut leaves you wondering if he could have ever really grown up.