to subdivide

from Bouvier's Law Dictionary, Revised 6th Ed (1856)
TO SUBDIVIDE. To divide a part of a thing which has already been divided. 
For example, when a person dies leaving children, and grandchildren, the 
children of one of his own who is dead, his property is divided into as many 
shares as he had children, including the deceased, and the share of the 
deceased is subdivided into as many shares as he had children. 
    

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