law: Transfer of Property Act, 1882
  13. Transfer for benefit of unborn person
  Where, on a transfer of property, an interest therein is created
  
  for the benefit of a person not in existence at the date of the transfer,
  
  subject to a prior interest created by the same transfer, the interest created
  
  for the benefit of such person shall not take effect, unless it extends to the
  
  whole of the remaining interest of the transferor in the property.
  Illustration
  A transfer's property of which he is the owner to B in trust for
  
  A and his intended wife successively for their lives, and, after the death of
  
  the survivor, for the eldest son of the intended marriage for life, and after
  
  his death for A's second son. The interest so created for the benefit of the
  
  eldest son does not take effect, because it does not extend to the whole of A's
  
  remaining interest in the property.