GIBBS C.J.: June May Fisher ("the wife") and Kenneth John Fisher ("the husband") were married on 30 October 1948. They lived together until 23 November 1983 when they separated and they did not cohabit thereafter. At the date of the separation the property of the spouses consisted of the former matrimonial home, which was in the name of the husband, two motor cars, one in the name of the husband and one in the name of the wife, and other items of personal property owned solely or jointly by the husband and the wife. On 17 February 1984 the wife filed an application in the Family Court of Australia seeking orders pursuant to s.79(1) of the Family Law Act 1975 (Cth), as amended ("the Act") for the alteration of the interests of the parties to the marriage in the property of the parties to the marriage. In particular, she sought an order that the matrimonial home be sold and that the proceeds of sale be divided equally between the husband and the wife and that other property of the husband and the wife be divided equally between them, or sold and the net proceeds divided equally between them. Certain procedural orders were made, but the proceedings on the application had not been completed when the wife died on 11 July 1984. She was survived by her son, Robert John Fisher ("the respondent"), a daughter and three grandchildren, the eldest of whom was aged eleven. By her will, the wife appointed the respondent to be the executor and trustee of her will, and gave all her jewellery to her daughter and the residue of her property to her trustee on trust for such of her grandchildren as should attain the age of twenty-five years. Probate of the will was granted to the respondent on 28 October 1984. On 30 April 1985 the respondent filed an application in the Family Court seeking, inter alia, an order, pursuant to s.79(8) of the Act and O.14 r.6 of the Family Law Rules, that he be substituted as a party to the proceedings commenced by the application made by the wife. The husband raised the question whether s.79(8) of the Act is valid and whether the Family Court had power to substitute the respondent as a party. Subsequently, the Attorney-General for the Commonwealth intervened in the proceedings. Thereafter Smithers J. stated a special case under s.94A of the Act for the opinion of the Full Court of the Family Court on two questions, which, in their amended form, are as follows: