CHAPTER VI 

 LANDSCAPE GARDENERS 



THAT changes in successive generations of animals 

 are largely due to the influence of their environment, 

 is a generally acknowledged fact; but it is equally 

 true that animals are often directly responsible for 

 changes in their own surroundings ; and the alterations 

 so produced sometimes remain in evidence long after 

 the species to which they are due has disappeared. 



The bison of the North American plains has ceased 

 to exist, but the pathways of the once innumerable 

 herds remain. In " The Deserts and Forests of North 

 America," Mr. Paul Fountain writes : 



" The plains are deeply scored with tracks, even to 

 this day, worn during countless generations by the 

 bisons, which seem always to have followed the same 

 routes in their migrations and wanderings. These 

 tracks are likely to endure, for the bison, with 

 wonderful sagacity, chose the easiest and safest paths, 

 avoiding barren bogs and crevices, so that travellers 

 invariably follow them. So deeply are these tracks 

 worn that, even if they were not kept fresh by the 

 frequent passage of horsemen and waggons, many 

 years would elapse before they were obliterated ; in- 

 deed, they may possibly be traceable for ever." But 



