Which family borron are you looking for. There are two, One appears below the A (attributes when and object is selected)it's a colored squared (grey in this case). The other button (select) is on the bottom row, next to the primative selecting buttons, a multi-colored square. If you can't find it there, hit the circular thingy on the end, you might have the animation menu up. (the 'select' and 'animation' menus occupy the same space in the Bryce workspace.