Section 1021. Substitution procedure; dismissal for failure to substitute; presentation of appeal

A motion for substitution may  be  made  by  the
  successors  or  representatives  of a party or by any party. If a person
  who should be substituted does not appear voluntarily he may be  made  a
  party defendant. If the event requiring substitution occurs before final
  judgment  and  substitution  is  not  made within a reasonable time, the
  action may be dismissed as to the party  for  whom  substitution  should
  have  been  made,  however,  such  dismissal  shall not be on the merits
  unless the court shall so indicate.  If the event requiring substitution
  occurs after final judgment, substitution may  be  made  in  either  the
  court  from  or to which an appeal could be or is taken, or the court of
  original instance, and if substitution is not made  within  four  months
  after the event requiring substitution, the court to which the appeal is
  or  could  be taken may dismiss the appeal, impose conditions or prevent
  it from being taken. Whether or not it  occurs  before  or  after  final
  judgment,  if  the event requiring substitution is the death of a party,
  and timely substitution has not been made, the court, before  proceeding
  further, shall, on such notice as it may in its discretion direct, order
  the  persons  interested  in the decedent's estate to show cause why the
  action or appeal should not be dismissed.