58 Soil- Binders 



are yet to be seen ; why, and when, they were destroyed 

 seems to be unknown, but the results were disastrous 

 and even alarming. At length, however, the happy 

 thought came to an engineer named Bre'montier, in 

 1787, that where trees had grown, trees might be 

 induced to grow again, and the attempt was made, 

 not with oaks, for they could not have borne the sand, 

 but with the maritime pine. Over and over again it 

 was tried and failed, owing to the shiftiness of the sand ; 

 but at length, by dint of immense perseverance, the 

 seed was induced to take root, and then the worst of 

 the battle was over. 



The pine-roots spread little by little, entangling the 

 sand and putting a stop to further rovings ; one dune 

 after another was brought to a standstill, and that 

 which threatened to become a desert has gradually 

 been converted into profitable pine-woods, with inter- 

 mediate stretches of vigorous heather and furze ten feet 

 high, and here and there a thick growth of hawthorn 

 and holly. 



We may conclude this chapter by mentioning the 

 curious origin ascribed to certain patches of grass 

 which occur frequently all over the bison region of 

 North America. These patches are said to be evidently 

 due to the bison's habit of wallowing in the dust, and 

 were, in fact, the wallowing places of the herd. The 

 repeated wallowing of a number of animals created 

 shallow hollows or depressions which the rain converted 

 into pools, where the water lingered and into which it 

 drained from the surrounding soil. Even when the 

 water had drained away the hollows would continue 

 damp for some time, and grass-seeds falling upon them 

 would readily spring up. The grass-plants would 



