... When a Roman marriage took place with the full ceremonies such as rendered divorce impossible, the names Caius and Caia always stood for those of the married pair in the formulary of prayer uttered over them while they sat on two chairs with the skin of the sheep newly sacrificed spread over their heads; and when the bride was conducted to her husband's house, spindle and distaff in hand, she was demanded who she was, and replied, "Where thou art Caius, I am Caia;" and having owned herself his feminine, she was carried over his threshold, to prevent the ill omen of touching it with her foot, and set down on a sheepskin within.  From this rite all brides were called Caiæ.  It is said that it was in honour of Tanaquil, whose Roman name was Caia Cæcilia, and who was supposed to be the model Roman woman, fulfilling the epitome of duties expressed in the pithy saying, Domum mansit, lanam fecit (she staid at home and spun wool), and was therefore worshipped by Roman maids and matrons... (History of Christian Names, Yonge, 1884)