As readers of Throw a Kiss, Harry will remember, Mary Chalmers' small hero is himself a cat, and so his Christmas request for a baby kitten is indeed a ""serious matter."" But Santa checks with Mother, and there is a flurry of preparation--buying bottles and blankets and booties, setting up a bassinet--before that gratifying ""meow"" is heard on Christmas morning. The rest is all expressive pictures, of anticipation contentingly fulfilled. It's a conventional, idealized story compared to the resonant moment that was Throw a Kiss. . .--but the sentiment that would swamp a human character is engagingly deflected in Harry.