I  believe  that  such  a  description  as  this  would  apply  to  most  of  the
warts  that  precede  epithelial  cancers  of  the  lower  lip,  and  that  we  may
justly  say  of  them  that  they  are  not  cancerous,  but  are  such  parts  as,
in  certain  persons,  are  peculiarly  apt  to  be  the  seats  of  cancer.  Why
only  some  among  them  should  become  cancerous  we  can  no  more  ex-
plain, than  we  can  why,  among  so  many  injuries  inflicted,  so  few  should
be  followed  by  erysipelas  or  tetanus ;  or  why,  among  so  many  pig-
mentary moles  or  nsevi  as  may  be  found,  only  few  should  become  the
seats  of  melanoid  cancer  ;  or,  in  a  yet  nearer  parallel,  why,  when  a
person  has  many  such  moles,  the  melanoid  cancer  should  appear  m  only
one.  In  these  varieties  of  fate,  there  is  nothing  unusual  in  warts  if  we
regard  them  as  only  predisposed  to  become  cancerous  ;  but,  if  we  re-
gard them  as  the  first  stages  of  a  cancroid  or  cancerous  disease,  such
varieties  of  progress  as  they  manifest  would  be  without  parallel.
(e.)  The  general  health  of  patients  with  epithelial  cancer  is  usually
good,  till  it  is  affected  by  the  consequences  of  the  local  disease.  Less
than  ten  per  cent,  of  them  appear  ill  at  their  first  observation  of  the
disease.  No  primary  cachexia  can  be  observed  preceding  the  appearance
of  the  growth  ;  nor  does  a  secondary  cachexia  ensue  earlier  than  it  pro-
bably would  in  any  disease  of  equal  duration  and  severity.
When  the  formation  of  an  epithelial  cancer  has  once  commenced,  its
natural  course  is  as  regularly  progressive  to  the  destruction  of  life  as
that  of  either  a  scirrhous  or  a  medullary  cancer.  Only,  the  rate,  and
some  parts  of  the  method,  of  progress  are  different.
