26 MR. W. G. CLARKE ON REMAINS OF THE NEOLITHIC AGE. 
it, on virgin heath-land, are two sandy hillocks, roughly 
rectangular in shape. Rabbits have honey-combed the outer 
slopes and thrown out an abundance of flints, almost every 
one being chipped. Among the flakes are fragments of rough, 
pottery, liberally besprinkled with grains of quartzite, and 
seeming to evidence a stage of culture early in the Neolithic 
Age. These elevated areas may possibly have been the 
sites of settlements ; the outer slope indicating the course of 
a ditch such as has been dug elsewhere under similar 
conditions. 
Ploughing seems to have had more to do with the possibility 
of finding implements than has the height of the heath-land 
above sea-level. Some of the most prolific patches are only 
about 30 feet above, this being particularly evidenced on 
Thetford and Santon Warrens, Rushford Heath, and at the 
foot of Bromehill. Implements at this level are numerous 
enough to show that the height to which the waters of the 
adjoining river rose in Neolithic times could not be more 
than 10 or 15 feet above their present levels. The tops of 
the ridges were apparently avoided by Neolithic man, who 
preferred the slopes, those facing north and east yielding 
quite as many implements as those facing south and west. 
Among the reasons for choosing certain sites for settlements, 
sandy soil and the proximity of water were seemingly 
prominent, although it should not be forgotten that in all 
probability some of the valleys which are now dry contained 
water-courses when Neolithic hunters roamed the district. 
Implements are found in more or less abundance on both 
sides of the Little Ouse between Brandon and Thetford ; 
but above the latter town the settlements are more sparsely 
distributed, many localities which to us appear eminently 
suitable yielding few or no implements. It seems almost 
useless to search for implements on heaths remote from the 
present rivers, or valleys connected with them. For this 
reason the large area variously known as Roudham, Bridgham, 
Brettenham, Kilverstone, and Croxton Heaths furnishes no- 
traces of occupation by Neolithic man. On the north-east 
side of Fowlmere, however, on a piece of elevated land which: 
