Section 1-2.16. Representation

By representation means a disposition or distribution of property made
  in  the  following  manner  to  persons  who take as issue of a deceased
  ancestor:
    The property so passing is divided into as many equal shares as  there
  are  (i)  surviving  issue  in  the  generation  nearest to the deceased
  ancestor which contains one or more surviving issue  and  (ii)  deceased
  issue  in  the  same  generation  who left surviving issue, if any. Each
  surviving member in such nearest generation is allocated one share.  The
  remaining  shares,  if  any,  are  combined and then divided in the same
  manner among the surviving  issue  of  the  deceased  issue  as  if  the
  surviving  issue who are allocated a share had predeceased the decedent,
  without issue.