private final char getRandomInstruction()
			{
				switch (Rand.int_(0, 20))
					{
						case 0:
							return ADD_NODE;
						case 1:
							return CLIMB_NODE_TREE;
						case 2:
							return DESCEND_NODE_TREE;
						case 3:
							return GROW_UP;
						case 4:
							return GROW_LEFT;
						case 5:
							return GROW_RIGHT;
						case 6:
							return GROW_DOWN;
						case 7:
							return NODE_CAN_SEED;
						default:
							return SKIP;
					}
			}