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 
