Fig. 45. A fern (Atpidium), showing three large branching leaves coming from a hori- 

 zontal subterranean stem (rootstock) : growing leaves are also shown, which are 

 gradually unrolling. The stem, young leaves, and petioles of the large leaves are 

 thickly covered with protecting hairs. The stem gives rise to numerous small roots 

 from its lower surface. The figure marked 3 represents the under surface of a 

 portion of the leaf, showing seven groups of spore cases ; at 5 is represented a 

 section through one of these groups, showing how the spore cases are attached and 

 protected by a flap ; while at 6 is represented a single spore case opening and dis- 

 charging its spores, the heavy spring-like ring extending along the back and over 

 the top.— After Wossidlo. 



