When Autumn turns the leaves to gold, there are few sights more stimulating than that of a lovely girl framed by nature's glories. Eighteen-year-old Kathy Douglas is such a girl. She is, in fact, one of that delightful number, The Girls of Hollywood, talked about in the pages up ahead. She divides her time more or less equally between acting assignments (she's under contract to a major studio) and the riding of a favored and favorite mount along seldom-trod California trails. When she is not accompanied on these excursions by a suitably nature-loving male, Kathy often packs along a book -- not the usual sticky novel but a volume of Bulfinch, since she digs mythology: an odd enthusiasm, perhaps, for a modern chick, but not for a latter-day wood nymph attuned so acutely to the autumnal symphony that she is a natural (in all senses of the word) Miss October.