Bringing Up Baby, directed by Howard Hawks in 1938, is one of the greatest screwball comedies and a treasure from the Golden Age of Hollywood. Cary Grant plays a naive and repressed palaeosaurologist who becomes entangled with (and ensnared by) a wilful heiress (Katharine Hepburn). Chaos ensues as romance blossoms and not one but two leopards are set loose in verdant Connecticut. All of Hawks's signature skills are to the fore: there is the wonderful ensemble cast, the characteristically refined but unselfconscious visual style, an endless succession of pratfalls, innuendo and jokes (written by Dudley Nichols and Hagar Wilde) and, underneath the chaos and good cheer, a serious dream of escaping life's troubles by dint of nothing more or less than nerve and luck.

There are no human babies in Bringing Up Baby, but there are those leopards and the relentless terrier George - and, as Peter Swaab explores in his witty and original study, Hawks's film wonders profoundly why we want animals in our lives and why we sometimes need to behave as animals ourselves. Many screwball films have been seen as comedies of remarriage, but Peter Swaab argues that this one is not much interested in marriage and is instead more captivated by instinct, irresponsibility and the wild abnormalities of romance.

The film is in its way an American dream of independence, and believes the real way to get on in life - for film-makers as well as scientists - isn't by deference and respectability but by having sexy fun with the right people. A thoroughly American fiction of the 1930s, Bringing Up Baby is also a timelessly classical comic narrative, exploring conflicts between civilisation and nature, rationality and insanity, middle-class inhibitions and aristocratic blitheness. And it is the epitome of film comedy, an anthology of comic types and devices, and one of the most seductively funny films ever made.