sentences:  During the summer and autumn of 1550, during which Gardiner was in the Tower of London, he wrote a retort which was presented to Cranmer at the conclusion of his trial in 1551.Gardiner was severely critical of Cranmer's arguments and cited a range of sources that he believed supported the doctrine of the corporeal presence of Christ in the elements of the Eucharist.Among these sources, were the Book of Common Prayer, Martin Luther, Cranmer's own catechism, and other Lutheran writers.