LIFE HISTORY OF A FERN 



161 



phyll departs from a foliage-leaf in appearance, it must, 

 nevertheless, be regarded as morphologically a leaf. As par- 

 tial evidence of the true foliar nature of sporophylls, there 

 may be cited the interesting experiment of Atkinson, who, 

 by removing the true foliage-leaves just beginning to unfold 



FIG. 121. A fern (Tectoria cicutaria) that bears bulbils on both the 

 upper and lower surfaces of its leaves. Plantlets develop from the bulbils 

 while they are still attached. 



in the spring, was able to induce developing sporophylls 

 to alter their character, and become transformed into 

 foliage-leaves. Similar results were also obtained by 

 Goebel. These experiments indicate that foliage-leaves 

 and sporophylls are very closely related to each other, 

 and demonstrate clearly that foliage-leaves may be 



ii 



