The outer cell continues to be a part of theepidermal layer whereas the inner derivative is incorporated intothe axial tissue. Further divisions of the primordial cells consistingof axial cells and the inner derivative of the periclinal division allowthe frond to grow rapidly. The daughter frond that is initiated as aprotuberance at almost right angles to the parent frond (Fig. 2d(ii))tends to face exactly opposite to its parent as it continues to growfurther as shown in Fig. 2b and c. For instance, the orientation offrond IIb is exactly opposite to its daughter IIIb’ (Fig. 2b).