Cambridge has been described by an appreciative American novelist as "a harmony in grey and green." And indeed it is true that few towns are so shot through and through with greenery. The London Road enters the place through two miles of umbrageous leafage; wide, open spaces of grass-land--Stourbridge Common, Midsummer Common, Coldham Common, Empty Common, Donkey Common, Peter's Field, Parker's Piece, Christ's Pieces, Jesus Green, Sheep's Green, Coe Fen--penetrate from the outskirts, north, south, and east, right to the heart of the town; while the world-famous "Backs," where the road runs beneath ancestral elms, between a continuous series of bowery College gardens and precincts--Queens', King's, Clare, Trinity, St. John's--with their beckoning vistas of long avenues of lime and chestnut, ring it in to the west, and form a scene of park-like loveliness to be found nowhere else on earth. Port Meadow, at Oxford, and the Magdalen Walks, furnish the nearest comparison; but only to show how far in front Cambridge stands in greenery. Even inside the Colleges this precedence shows itself; for in Cambridge every College Court in the place, almost without exception, unlike so many of the "Quads" of Oxford, has its central grass-plot. These lawns, it may be noted, are sacrosanct, not to be profaned by the foot of anyone but a Fellow of the College[1] itself. No outsider, from another College, however high in academic rank, may, unless accompanied by a Fellow, cross over them; still less any member of the College, old or young, who is not himself a Fellow, nor any casual visitor, even of the privileged sex. Should any such attempt be made, the College porters will politely, but quite firmly, remove the transgressor. This convention is absolutely necessary for the very existence of the greensward, which, if allowed to be traversed by all-comers, would speedily be cut up and ruined. [Footnote 1: The word "Fellow" signifies, in any College, one of the strictly limited corporation to whom its whole property legally belongs. This corporation is kept filled up by co-option; the most distinguished of the junior students being usually chosen.]