Some day Marshall McLuhan or Russell Baker may tell us why the cat is suddenly such astonishing good news at the box office. Here are two lavishly illustrated anthologies of notable tributes to Fells catus, and they could not be more different. Both include such old friends as Thomas Gray's epitaph for a drowned goldfish-chaser, Kipling's ""The Cat That Walked by Himself,"" and the ""Jeoffrey"" section from Christopher Smart's Jubilate Agno. But The Literary Cat is basically a collection of lovable Chandoha photographs (140 of them, in black and white) interspersed with harmless morsels--extended captions, really--from Richard Armour, Gladys Taber, Rod McKuen, and a few more substantial tidbits from May Swenson, Don Marquis, Adlai Stevenson (the celebrated veto of an Illinois Senate bird-protection bill), and even Faulkner (a lovely aside from The Reivers). The Book of Cats, put together by a pair of cat-loving British poets, is altogether a more adventurous (and literary) affair. It sashays elegantly through the doings of P. G. Wodehouse's Webster, Eliot's Macavity and Growltiger, de la Mare's Sam (""Broomsticks""), Saki's Tobermory, and W. W. Jacobs' ""The White Cat."" There are marvelous detours through Sartre, Aldous Huxley (the ""human truths"" any aspiring novelist can find in cat behavior), Fielding, and Dorothy Sayers (a charming fit of versified exasperation about feline persnicketiness). The inevitable selections from Smart, Gallico, and Don Marquis are more generous and more spirited than those in the Chandoha collection. The illustrations (115 black and white, 16 color) run a glorious gamut from the wicked hunter in Bosch's Garden of Earthly Delights to Charles Addams' sybarite with mouseskin rug. The entire collection strikes a note of genial and unforced sophistication; the Chandoha book is as placid and pretty as a sleeping Persian. To think that cat-lovers would ever be divisible into middlebrow and highbrow audiences. . . .