202 BRITISH SERPENTS. 
absent, and the adder common and of large size in 
the Monnow Valley ? 
1. Natural boundariws.—In the case of a small 
inland area these are the topographical factors of 
rivers, mountains, woods, and cultivated land. The 
influence of such factors is at once evident in a case 
such as the one under consideration. This valley is 
approached from all directions through more or less 
cultivated parts, highly so in several directions, and is 
far more sparsely populated than the surrounding parts 
of the counties. The transition is sharp from arable 
or ploughed land to mountain and woodland. Ob- 
viously as civilisation advanced towards the valley 
from all sides, as the land became cleared and the 
plough succeeded the axe, the wilder animals, which 
shun the approach of man, would retire before him; 
and here at the northernmost point of Monmouthshire 
and the south border of Herefordshire, coming from 
both directions, these animals found a shelter in the 
secluded valley, and in the thick and extensive woods 
of Garway Hill and The Graig. To this day the latter 
hill is the home of the foxes in the district, and, as 
the Master and members of the Monmouthshire Hunt 
know only too well, it is a nearly hopeless task for men 
or hounds to turn an old fox out of his haunts in the 
thick woods on The Graig. So that from the point of 
view of natural boundaries, here is a place where one 
would expect the most retiring animals to congregate 
and make a last stand. 
