Golding  Bird  has  shown  that  phymosis,  by  obstructing  the  free  exit  of
urine,  may  give  rise  to  these  signs  and  to  extreme  hypertrophy  of  the
bladder ;  but  in  some  cases  it  appears  certain  that  hypertrophy  may
occur  without  either  phymosis,  calculus,  stricture,  or  any  similar  ob-
struction. It  was  so  in  a  case  illustrated  in  the  Museum  of  St.  Bartho-
lomew's (xxvii.  14),  in  a  child  four  years  old,  who  had  suffered  intensely
with  signs  of  stone  in  the  bladder,  but  in  whom  no  stone  existed  ;  no
disease  of  the  urinary  organs  could  be  found,  except  this  hypertrophy
of  the  muscular  coat  of  the  bladder.  An  exactly  similar  case  was  under
Mr.  Stanley's  care,  in  which,  after  exceeding  irritability  of  the  bladder,
the  enlargement  of  its  muscular  coat  appeared  the  only  change.
In  such  cases,  the  too  frequent  and  strong  action  of  the  bladder,
though  irritable  and  unhealthy,  seems  alone  to  give  rise  to  hyper-
trophy of  the  fibres.  It  is,  however,  possible  that  the  change  may  be
due  to  temporary  closure  of  the  urethra  by  muscular  action.  If,  for
example,  the  compressors  of  the  urethra,  instead  of  relaxing  when  the
muscular  coat  of  the  bladder  and  the  abdominal  muscles  are  contract-
ing, are  in  the  habit  of  contracting  with  them,  the  obstacle  they  would
produce  in  the  urethra  will  soon  engender  hy^aertrophy  of  the  bladder.
