A is making his last will. He wants to leave his cottage property to his daughter and her husband, but in such a

way that neither of them can deal with the property without the consent of the other and that when one of them

dies, the other will become the owner of the property. He also wants to leave his country house for the use and

possession of his son during his son's lifetime, and after that to his niece and her husband, although he wants to

specify that his niece will have an undivided 85 percent interest in the country house and her husband an

undivided 15 percent interest. What type of interest and estates will the beneficiaries have in A's property?