Bringing Up Baby showcases what is probably the most ridiculous of all of the “adventures” we’ve seen in these films so far. I think the theme of seclusion in these movies is interesting–for Hepburn and Grant to have their adventure, they run away to Connecticut (Hepburn essentially kidnaps Grant). This had to happen in order for them to fall in love; had they not run away, Mr. Bone would have married Ms. Swallow.
The same themes of running away and being in seclusion pop up in It Happened One Night and The Lady Eve, and even in the James Joyce stories (in the sense that Eveline needs to be “rescued” from her current situation–she cannot find happiness where she is). This makes me think of A Midsummer Night’s Dream, where all common sense and “natural behavior” is turned on its head when the characters enter an enchanted forest. The road trip in It Happened One Night, the boat in The Lady Eve, and the farm house in Connecticut in Bringing up Baby all serve a similar purpose. They remove all outside distractions (Grant’s fiancee, for example) and allow the characters to truly “fall in love.”
This makes sense if we think of marriage as a social construct, and the characters in these films as challengers of that social construct. They have to be removed from society and put into a kind of magical setting in order to find true love.