SOUTHERN RHODESIA BREAKING THE RULES SHE WAS PICKING CORN . HE WAS WATCHING . " IT WAS NOT LOVE AT FIRST SIGHT, " RECALLS STUART FULLER-SANDYS, 50, OF HIS FIRST GLIMPSE OF MARGARET DUBE, 22 . " LOVE CAME LATER LIKE A DELUGE . " THERE WAS ONLY ONE SERIOUS COMPLICATION : SHE WAS BLACK, AND HE WAS WHITE . ON THE FRONT PAGES OF EVERY SOUTHERN RHODESIA PAPER LAST WEEK WAS THE FAIRYTALE ROMANCE OF THE RICH, WIDOWED WHITE RANCHER TO THE PENNILESS DARKY DAUGHTER OF ONE OF HIS SQUATTER TENANTS . IT BEGAN IN 1961, AND HAD PYGMALION OVERTONES . IN HIS IRON-ROOFED BIG HOUSE, FULLER-SANDYS, LIKE HENRY HIGGINS, DAILY GAVE MARGARET LESSONS IN THE SOCIAL GRACES OF THE REGION . MARGARET LEARNED TO SPEAK AND READ, SLOWLY MASTERED THE ASSEMBLY OF CUTLERY FOR A FOUR-COURSE DINNER . FOR HOURS, TEACHER AND PUPIL PORED OVER ARITHMETIC PRIMERS, ENCYCLOPEDIAS AND FASHION MAGAZINES . ONE EVENING FULLER-SANDYS GAZED AT HER IN A SPECIAL WAY ; SHE SAID YES AND IN ENGLISH . PROMPTLY FULLERSANDYS CALLED ON HER GNARLED FATHER, AN AGED AND RESPECTED LABORER ON THE PLACE . NATURALLY, FULLER-SANDYS HANDED OVER A BRIDE PRICE ($100) ; THEN FULLER-SANDYS SLIPPED A DIAMOND ENGAGEMENT RING ON MARGARET'S FINGER . IT WAS A BRAVE STEP IN WHITE-RULED SOUTHERN RHODESIA . IMMEDIATELY THE GOVERNMENT FIRED FULLER-SANDYS AS AN ADVISER IN THE NATIVE AFFAIRS DEPARTMENT, CURTLY EXPLAINING : " YOU CANNOT ADMINISTER AFRICANS AND SLEEP WITH THEM . " OF 48 WHITE FRIENDS FULLER-SANDYS INVITED TO THE WEDDING LAST WEEK, 34 SENT THEIR REGRETS . THE BEAMING BRIDE, CARRYING A BOUQUET OF WHITE DAHLIAS AND WEARING A WHITE SATIN GOWN, HAD THREE AFRICAN BRIDESMAIDS FOR THE CEREMONY ON FULLER-SANDYS'S VERANDA, PERFORMED BY THE REV . RICHARD HUGHES, RECTOR OF AN ANGLICAN CHURCH AT QUE QUE 64 MILES AWAY . THAT NIGHT, UNDER A FULL MOON, THE WEDDED COUPLE ATTENDED AN AFRICAN CELEBRATION IN THEIR HONOR . THERE WAS MUCH LEAP-DANCING AND YELLING AROUND A CAMPFIRE . DURING THE EVENING FULLER-SANDYS HAD A CHANCE TO OPEN A LETTER DELIVERED TO HIM EARLIER IN THE DAY . BEARING NEITHER RETURN ADDRESS NOR SIGNATURE, IT SAID, " YOU BLOODY WHITE KAFFIR, WHAT A DISGRACE TO THE COUNTRY YOU ARE . . . YOUR BELOVED BLACK BASTARD ISN'T EVEN GOOD LOOKING . " HE READ THE NOTE, THEN HANDED IT TO HIS BRIDE . AFTER A MOMENT, SHE REPLIED QUIETLY : " IT DOESN'T MATTER, DEAR . /