"The love impulse in man," says a psychiatrist in Bringing Up Baby, "frequently reveals itself in terms of conflict." That's for sure. For a primer on the rules and regulations of the classic screwball comedy, which throws love and conflict into close proximity, look no further. A straight-laced paleontologist (Cary Grant) loses a dinosaur bone to a dog belonging to free-spirited heiress Katharine Hepburn. In trying to retrieve said bone, Grant is drawn into the vortex surrounding the delicious Hepburn, which becomes a flirtatious pas de deux that will transform both of them. Director Howard Hawks plays the complications as a breathless escalation of their "love impulse," yet the movie is nonetheless romantic for all its speed. (Hawks's His Girl Friday, also with Grant, goes even faster.) Grant and Hepburn are a match made in movie heaven, in sync with each other throughout. Not a great box-office success when first released, Bringing Up Baby has since taken its place as a high-water mark of the screwball form, and it was used as a model for Peter Bogdanovich's What's Up, Doc? --Robert Horton