199 



obtainable as to variation in the conditions of the 



eeps his eye constantly open to the possible dis- 

 covery of organic remains in the terraces, more especially 

 in those of greater altitude, wlu. h U-mg the oldest ought 

 to contain the earliest forms of !;! kmlcly hipped 

 Mini instruments, or more deftly- fashioned celts occurring 



I 



in the undisturbed strata of a terrace, prove that man 

 inhabited the district when the river flowed over these 

 strata. 



Ancient Btafh-lixct. Reference has already been 

 made to the manner in which former levels of the land 

 are marked by terraces containing marine organisms 

 (p. 87). It is obvious that if the land stood long 

 enough at a particular level, the action of the waves might 

 in some places cut a notch along the coast-line as well as 

 spread out a terrace of sand and gravel below high-water 

 mark. The observer may detect many such beach-lines 

 along the coast of Scotland, and the fiords of Norway. H - 

 will mark whether they consist of a platform (Norwegian, 



levelled out of the rock, with a cliff (some 

 perforated with caves) behind it, or whether, the com: 

 for accumulation of sediment having been favourable, 

 they present a level or gently-sloping terrace of sand and 

 gravel (raised beach). Along the west coast of Scotland 

 these various lines of former sea-margin, sometimes in 



