At this period Peterhouse consisted of two courts, separated by a wall occupying the position of the present arcade at the west end of the chapel. The westernmost or principal court is, save in some small details, that which we see to-day. The small eastern court next to the street has undergone great alteration by the removal of certain old dwelling-houses--possibly relics of the original hostels--fronting the street, which left an open space, occupied at a later period partly by the chapel and by the extension eastward of the buildings on the south side of the great court to form a new library, and subsequently by a similar flanking extension on the north. The earliest of these buildings was the library, due to a bequest of Dr. Andrew Perne, Dean of Ely, who was master of the College from 1553 to 1589, and who not only left to the society his own library, "supposed to be the worthiest in all England," but sufficient property for the erection of a building to contain it. Perne had gained in early life a position of importance in the University--he had been a fellow of both S. John's and of Queen's, bursar of the latter College and five times vice-chancellor of the University--but his success in life was mainly due to his pliancy in matters of religion. In Henry's reign he had publicly maintained the Roman doctrine of the adoration of pictures of Christ and the Saints; in Edward VI.'s he had argued in the University pulpit against transubstantiation; in Queen Mary's, on his appointment to the mastership of Peterhouse, he had formally subscribed to the fully defined Roman articles then promulgated; in Queen Elizabeth's he had preached a Latin sermon in denunciation of the Pope, and had been complimented for his eloquence by the Queen herself. No wonder that immediately after his death in 1589 he should be hotly denounced in the Martin Marprelate tracts as the friend of Archbishop Whitgift, and as the type of fickleness and lack of principle which the authors considered characteristic of the Established Church. Other writers of the same school referred to him as "Old Andrew Turncoat," "Old Father Palinode," and "Judas." The undergraduates of Cambridge, it is said, invented in his honour a new Latin verb, _pernare_, which they translated "to turn, to rat, to change often." It became proverbial in the University to speak of a cloak or a coat which had been turned as "perned," and finally the letters on the weathercock of S. Peter's, A.P.A.P., might, said the satirists, be interpreted as Andrew Perne, a Protestant, or Papist, or Puritan. However, it is much to be able to say that he was the tutor and friend of Whitgift, protecting him in early days from the persecution of Cardinal Pole; it is something also to remember that he was uniformly steadfast in his allegiance to his College, bequeathing to it his books, with minute directions for their chaining and safe custody, providing for their housing, and moreover,