Yol.  49.]  GRANITE  IN  THE  GABBRO  OF  THE  CUILLIN  HILLS.  189 
portion  and  the  bluish-grey  mass  in  the  centre,  which  appears  to  be 
coloured  by  magnetite  and  finely-divided  pyrite. 
Spherulites  from  less  than  1  millimetre  up  to  60  centimetres  in 
diameter  and  of  all  intermediate  sizes  can  be  found ;  and  sometimes, 
as  may  be  well  seen  in  weathered  surfaces  of  the  rock,  the  mass  is 
made  up  of  crushed  and  distorted  spherulitic  growths  like  those 
occurring  in  Silver  Cliff,  Colorado1 2  (PI.  II.  fig.  3).  These  indi¬ 
cate,  as  has  been  shown,  that  the  mass  was  subject  to  internal 
Section  of  the  Granite-nucleus  of  a  Spherulite  (see  PL  III. 
figs.  12  and  13),  as  seen  with  a  magnifying  power  of  14 
diameters. 
The  quartz  and  the  micropegmatite  groups  are  almost  unaltered  and  retain 
their  relative  position,  only  a  small  quantity  of  glass  having  been  pro- 
duced  by  the  fusion  of  intervening  materials. 
movement  during  the  time  that  the  spherulites  were  being  formed. 
Hollow  spherulites  or  lithophyses,  especially  types  like  the  beautiful 
forms  that  have  been  compared  to  an  expanding  rose,'  are  by 
no  means  uncommon  (see  PL  II.  fig.  5).  There  are  examples  in 
which  globular  aggregates  of  small  spherulites  up  to  25  millimetres 
1  Whitman  Cross,  op.  supra  cit.  pi.  v.  fig.  1. 
2  J.  P.  Iddings,  ‘  Obsidian  Cliff,  etc.,’  pi.  xii. 
