LEAF-BEGINNINGS AND LEAF-FORMS 



249 



IE. Step. 



FIG. 305. SCALY SPLEENWOKT (Asplenium ceterach). 



ck of the frond is covered with golden-brown chaffy scales, which protect it before expansion and when it rolls up 

 as though dead in dry weather. EUROPE, N. AFRICA, w. ASIA, HIMALAYA. 



leaves at the margin, and every full-sized leaf, even when growing on the 

 parent plant, exhibits at each of the notches a group of cells the embryo 

 bud which to the naked eye appears like a speck. When one of these 

 leaves is removed and placed in a moist situation, the buds develop and 

 leafy shoots appear ; while the old leaf soon falls to decay, and the young 

 plants become independent and self-supporting. 



A New Zealand Fern, Asplenium bulbiferum, is likewise noted for its 

 budding propensities. The buds are borne on the, divisions (pinnules) of 

 the older fronds, which are so proliferous that a single plant may be the 

 parent of many hundreds of new individuals. Other Ferns as Aspleniutn 

 edgetvorthii, Ceratopteris thalictroides, Gleichenia cryptocarpa, G. flabellata, 

 and G. cunninghami display the same vital energy : -indeed, there is reason 

 for believing that a fern-frond is simply a cladode or flattened branch, and 

 that the buds are normally produced like the flower-buds of the cladodes 

 of the Butcher's Broom. A graceful North American species of Hart's- 

 tongue Fern known as the Jumping-leaf (Scolopendrium rhizophyllum) 

 usually produces buds at the ends of its narrow lanced-shaped fronds. The 

 fronds bend over until their slender tips touch the ground, when roots form 



