細菌延伸 bacterial extension

a點固定，控制b點的位移改變細菌的長度;控制由a、b兩點為圓心相互消長的圓變動改變細菌的厚度。長度和厚度在一個週期（分裂期間）裡互為反比。

Point a is fixed, by controlling the displacement of point b to change bacterium's length; by controlling the circles which take point a,b as the center to mutual increase and decrease to change bacterium's thickness. The length and thickness in one cycle (division period) are inverse proportions mutually.