1. A city or town may validly annex by ordinance a tract of land all of which was included in, although smaller than, the tract described in the petition for annexation. 2. An ordinance purporting to annex property not described in the petition for annexation is void. Such a void ordinance cannot be vitalized by amendment. 3. Unless conditions have materially changed so as to make annexation now disadvantageous, there is no legal impediment to the reenactment of the ordinance of annexation based upon the original petition and hearing.