120 NEOZOIC TIME. [CHAP. VIII. 



he is acquainted with, but that they closely resemble the 

 quartzites of the Highlands of Scotland, pebbles of which 

 are common in the Old Eed and Lower Carboniferous con- 

 glomerates of central and southern Scotland. He has also 

 found pebbles of a quartz-felspar grit, which can only be 

 compared with the harder parts of the Torridon sandstone, 

 so that he thinks the currents which carried the pebbles 

 came from the north. 



Mr. Harrison, however, argues that the pebbles have 

 been derived from the Palaeozoic rocks which underlie the 

 Trias in the Midland and Eastern counties. He points to 

 the fact that the pebbles are largest in the Midlands, and 

 decrease in size as the beds are traced northward, and he 

 has also found quartzites which contain Devonian fossils 

 similar to those in the Budleigh Salterton pebbles. These 

 are undoubtedly strong arguments against the northern 

 derivation of the pebbles, at any rate against the idea of 

 their having all been transported from the north in 

 Triassic times. 



It is possible, however, that both observers may be right, 

 and that the conflict of opinion may be more apparent 

 than real. Professor Bonney rests his opinion chiefly upon 

 the remarkable correspondence of the quartzites with certain 

 rocks which only occur in situ in Scotland, but he admits 

 that they are not likely to have been derived directly from 

 these rocks in Triassic times. In point of fact, they may 

 have had more than one resting-place before reaching their 

 present location ; some of them may have been primarily 

 embedded in the Lower Old Eed Sandstone, and may from 

 this have been washed into the Upper Old Eed and Car- 

 boniferous conglomerates. Now the latter are known to 

 contain rocks of Scotch origin as far south as the Isle of 

 Man, Westmoreland, and north-west Yorkshire. It is 

 quite possible, therefore, that such pebbles may have been 

 carried as far south as Derbyshire, and may, for ought we 



