A per stirpes disposition or distribution of property is made to
persons who take as issue of a deceased ancestor in the following
manner:
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
share of a deceased issue in such nearest generation who left surviving
issue shall be distributed in the same manner to such issue.