Two novellas with the instant momentum of first talent and first experiences at the level of impulse rather than insight. In ""Party Party"" (""It's different now, isn't it?"" ""Very different""), Danny Yoder raps with Allegra's brother Roger about Allegra, sluttish and sodden on the one hand, sweet and wifely on the other. Allegra just ""pops, maddens, changes and disappears""--in fact, has--but where? Into the bed of an older man or that of an institution? The tone changes in ""Girlfriends,"" new girlfriends--Isabel, who is older and has a straying husband, three children and handfuls of Valiums to get her through the day, and Zimmie, the hippie she meets one evening, who is a very pregnant unmarried-housewife-welfare-mother-to-be. It's Zimmie's nativity which is the peak moment here, just as Zimmie's irrepressible spirit--she's funny, untrammeled and altogether alive--carries the book and leaves you with a natural high. So give in gracefully and groove along--you'll find that youth has the distinct advantage.