258 ADVENTURES AMONG BIRDS 



had domestic animals and agriculture, found the 

 chalk hills a better place than the lowlands, covered 

 as they must then have been with a dense forest 

 growth, the habitation of wolves and other rapacious 

 beasts. On the hills where the thin soil produced 

 only a dwarfish tree vegetation, it was easier to make 

 a clearing and pasture for his cattle. No doubt it 

 was also easier for him to defend himself and his 

 possessions against wild beasts and savage human 

 enemies in such situations. The hills were without 

 water, but the discovery and invention of the dew- 

 pond, probably by some genius of the later Stone 

 Age, made the hill-people independent of natural 

 springs and rivers. In later times, when the country 

 was everywhere colonised and more settled, the hill- 

 people probably emigrated to the lower lands, where 

 the ground was better suited for cattle-grazing and 

 for growing crops. The hills were abandoned to the 

 shepherd and the hunter; and doubtless as the ages 

 went on they became more and more a sheep-walk; 

 for it must have been observed from early times that 

 the effect of the sheep on the land was to change its 

 character and to make it more and more suited to 

 the animal's requirements. Thus, the very aspect of 

 the downs, as we know them, was first imparted and 

 is maintained in them by the sheep — the thousands 

 on thousands of busy close-nibbling mouths keeping 

 the grass and herbage close down to the ground, and 

 killing year by year every forest seedling. And how 

 wonderful they are — that great sea of vast pale green 

 billowy hills, extending bare against the wide sky 



