Vol.  49.]  CRYSTALLINE  SCHISTS  OF  THE  MALVERN  HILLS.  425 
made  that  point  clear  in  his  hasty  summary  of  a  long  paper  ; 
this  change  was  shown  by  the  study  of  numerous  sections  and 
specimens,  which  demonstrated  an  unbroken  passage  between  the 
two  extremes ;  and  the  potash  for  the  conversion  of  chlorite  into 
biotite  was  supplied  by  the  adjacent  granite,  while  the  iron  was 
furnished  by  the  decomposition  of  the  hornblende  of  the  diorite. 
To  Mr.  Harker  he  replied  that  the  gradations  described  were 
shown  by  very  exhaustive  enquiry  in  the  field,  as  well  as  by  micro¬ 
scopic  slides. 
In  answer  to  Mr.  Kutley’s  observations,  he  pointed  out  that 
corrosion  was  not  necessarily  connected  with  schist-making,  but 
as  a  matter  of  fact  it  was  so  in  the  Malvern  area.  The  dis¬ 
tinction  between  primary  and  secondary  injection  was  not  hypo¬ 
thetical,  but  was  based  upon  clear  evidence.  The  banding  of  diorite 
by  granite-veins  took  place  on  a  large,  as  well  as  upon  the  small 
scale ;  and  the  grit  of  Eagged  Stone  Hill  was  not  sedimentary, 
but  could  be  traced  into  crushed  diorite. 
In  reply  to  Prof.  Hull,  the  Author  remarked  that  the  conversion 
of  chlorite  into  biotite,  asserted  by  him  in  1889,  had  been  con¬ 
firmed  by  the  researches  of  Salomon,  Lossen,  Eiidermann,  and  other 
foreign  observers. 
In  conclusion,  the  Author  stated  that  his  views,  however  heretical 
they  might  appear  to  some  of  the  speakers,  were  based  upon  six  or 
seven  years’  careful  work  in  the  field,  the  cabinet,  and  the  labora¬ 
tory  ;  and  he  asked  that  his  paper  and  his  specimens  should  be 
studied,  before  a  decided  opinion  was  formed  by  his  critics. 
* 
Q.  J.  G.  S.  Ho.  195. 
