To many charming byways amid the streamlets and the meadows and the gentle slopes of this southern Cambridgeshire the seven highways out of Cambridge will successively conduct us. The highways themselves are, as has been said, seldom inspiring thoroughfares, save for their far-flung horizons; and the Newmarket Road least of all, for it is, as might be looked for, motor-swept beyond all the rest. The one near-hand object alone worth mention is the little Church of Quy, whose far-seen tower dominates some miles of the road. But this has little interest except its curious name, which is matter of dispute amongst etymologists. "Cow-ey" is the most commonly accepted derivation, meaning the Island of Cows. But Quy can never have been an island. More probably it is "Cow-way," like the "Cowey Stakes" on the Thames, signifying that here was a passage for cattle across the marshy ground which bordered the little stream crossed by the road before reaching the church. This stream flows out of Fulbourn Fen, an isolated patch of fen-land a mile square, even yet only half reclaimed, and of old so impassable that it determined the line of the great Fleam Dyke, which runs up to it on either side but does not need to cross it. [Illustration: _Quy Church._] The Fleam Dyke is one of the great prehistoric lines of defence which were run from the Fens of the Cam to the summit of the East Anglian heights. Those heights were in ancient times clothed with dense forest, and formed an impenetrable barrier against enemies from the west seeking to invade the East Anglian districts. So too did the morasses of the fenland. But between fen and forest stretched a strip of open grassland furnishing easy access. To defend this, the only gate into their territory, was the great object of the inhabitants of those districts; and they ran across it two stupendous earthworks, the Fleam Dyke as their outer bulwark and the Devil's Dyke, which we meet at Newmarket, as the inner.[124] The former stretches for a length of some ten miles from the banks of the Cam at Fen Ditton to the uplands by Balsham (its course broken by Fulbourn Fen); the latter ranges in a long unbroken rampart from the Fen at Reach to Wood Ditton (_i.e._ "the ditch-end in the forest"). [Footnote 124: There were other minor Dykes (such as the Warstead Street, from Cherry Hinton to Horseheath), but these play no part in history.]