182 
PROP.  J.  W.  JUDD  ON  INCLUSIONS  OP  TERTIARY  [May  1 893, 
clature  of  Eosenbusch)  ‘granophyre.’1  This  drusy  and  micropeg- 
matitic  variety  of  the  rock  passes  in  turn  into  ordinary  quartz- 
feisites  ( quarz-porphyr ). 
The  gabbros  of  the  same  district  have  been  already  described  at 
some  length  in  a  former  volume  of  this  Journal,  and  I  may  there¬ 
fore  refer  to  that  memoir  for  full  petrographical  details.2  The 
rocks  are  very  typical  gabbros,  exhibiting  every  gradation  from 
augite-gabbro  to  common  or  diallage-gabbro ;  and  the  raonoclinic 
pyroxene  is  to  a  greater  or  less  extent  liable  to  be  replaced  by  a 
rhombic  variety  (bronzite  or  hypersthene),  so  that  the  rocks  pass 
into  norites. 
4.  The  Position  and  General  Characters  op  the  Granite- 
inclusions  in  the  Gabbro. 
The  locality  where  the  inclusions  of  granite  can  be  seen  lying  in 
the  midst  of  the  gabbro  of  the  Cuillin  Hills  is  known  as  Druim-an- 
Eidhne  (see  the  sketch-map  on  the  preceding  page,  which  has  been 
reduced  from  the  latest  edition  of  the  six-inch  Map  of  the  Ordnance 
Survey).  That  ridge,  Avhich  is  rather  more  than  1000  feet  in  height, 
is  situated  in  the  angle  formed  by  the  valley  in  which  the  well- 
known  Loch  Coruisk  lies,  by  the  scarcely  less  famous  Harta  Corrie, 
and  by  the  continuation  of  Glen  Sligachan  called  Strath-na- 
Creitheach.  The  ridge  itself  is  composed  of  a  great  intrusive  sheet 
of  gabbro  overlying  the  acid  rocks,  which  rise  from  beneath  it 
northward  into  the  mountain  of  Meall  Dearg.  At  many  points 
the  junction  between  these  bare  and  strongly-contrasted  rocks  may 
be  easily  followed.  The  gabbro  at  this  locality  presents  all  its  usual 
features  ;  the  only  noteworthy  peculiarity  being  the  great  abundance 
in  it  of  contemporaneous  or  segregation-veins,  an  occurrence  long 
ago  pointed  out  by  Maceulloch.  The  granitic  rock  of  Meall  Dearg 
is  the  drusy  and  micropegmatitic  variety  of  augite-granite,  so  widely 
developed  in  this  district,  and  it  passes  in  places  into  a  true  quartz- 
felsite  or  ‘  quartz-porphyry ’  with  idiomorphic  crystals  of  quartz  and 
felspar. 
Well  within  the  boundary  of  the  gabbro,  and  sometimes  at  the 
distance  of  many  yards  from  it,  there  occur  a  number  of  irregular 
patches  of  pale  granitic  rock,  which  are  seen  to  be  completely  en¬ 
closed  in  the  gabbro  mass.  These  enclosed  patches  are  sometimes 
at  least  20  or  30  yards  from  the  line  of  junction  between  the 
1  Unless  the  terminology  of  petrography  is  to  be  allowed  to  fall  info  a  state 
of  utter  confusion,  a  confusion  ten  times  worse  confounded  than  that  which 
has  characterized  it  in  the  past,  a  protest  and  a  firm  stand  must  be  made  against 
the  practice — especially  prevalent  in  Germany — of  taking  old  names  and  re¬ 
defining  them  so  as  to  express  ideas  totally  different  from  those  of  the  original 
authors.  It  may  now  be  too  late  to  restore  to  ‘gabbro’  and  ‘syenite’  their 
original  significations  ;  but  ‘grauitite’  and  ‘  granophyre,’  if  used  at  all,  must 
surely  be  employed  with  the  meaning  given  them  by  their  respective  authors, 
Gustav  Eose  and  Vogelsang.  See  on  this  point  the  admirable  remarks  of 
Whitman  Cross  (Bull  Phil.  Soc.  Washington,  vol.  xi.  p.  430,  note). 
2  Vol.  xlii.  (1886)  pp.  49-97. 
