14-8 ASSOCIATIONS OF [Ch. VIIL 



vary much in size ; and differ completely in aspect from those 

 accumulated plates of mica, which are found in the granite of 

 Aberdeen, as well as in many other granites. In other cases, 

 the imbedded fragments consist of the same quartz-rock and 

 gneiss which form the general body of these schistose rocks. 

 The head of Loch Spey, a tract far removed, yet possibly not 

 unconnected with this, is also composed of granite; and 

 among this are found perfect granitic conglomerates, in which 

 fragments of mica-schist, equalling in quantity the substance 

 which connects them, are seen imbedded in a paste of granite. 

 Occasionally these fragments are confounded with the granite 

 at their edges; but at times are so defined, and even so 

 separable, that I procured a specimen with a distinct vacant 

 impression of a rectangular fragment, which had probably 

 been detached; as cavities left in this way, by the wearing 

 out of the schist, occur frequently in the rocks of the moor of 

 Rannoch. * 



Although the schistose rocks are seen only at the two ends 

 of this prolonged tract of granite, the imbedded fragments 

 can be traced throughout the whole. Dr. Macculloch adds, 

 " that if any one be unwilling to consider these imbedded 

 portions of schist as fragments, it can only be said, that if they 

 were really detached fragments, they could possess 110 other 

 aspect than that which they now have." 



In short, the occurrence of angular and rounded portions 

 of schistose rocks in granite has been observed in almost every 

 primary country, exhibiting various appearances, according to 

 their size and the proportion which they bear to that of the 

 containing mass. " The granite of Braemar, of Aberdeen, 

 and of other districts n Scotland," says Professor Jameson, 

 contains portions of gneiss, mica-slate, clay- slate, and also of 

 porphyry, syenite, and trap, varying in size from a few inches 

 to many fathoms. These masses are to be seen passing by 

 imperceptible shades into the bounding granite; thus showing 



* Geol. Trans., vol. iv. p. 126. et se<j. 



