ASPIDIUM SPOROPHYTE 287 



B. FILICINE^E 



I. Homosporous Type 



ASPIDIUM FILIX-MAS (The Male Shield 

 Pern) 



A. MATURE SPOROPHYTE 



I. External Characters 



I. Taking a well-grown plant of the common Male 

 Fern in summer, wash the soil away from the roots, and 

 observe the following external characters : 



A. The stem is oblique and ascending: it is not 

 branched at its apex : its surface is covered by the 

 persistent bases of the leaves, which are densely 

 covered by numerous brown scaly hairs (paleae or 

 ramenta). 



B. The leaves, the most prominent of which are 



i. The fully-developed green leaves of the current 

 year : these are large and of complicated structure 

 and the following parts may be recognized : 



a. A long almost cylindrical leaf-stalk, which is 

 traversed by two longitudinal, lateral ridges or reduced 

 wings. This leaf-stalk supports 



&. The numerous pinnae, which are arranged in two 

 lateral rows, corresponding in position to the lateral 

 ridges above mentioned : note that the arrangement of 

 the nerves in the segments of the pinnae is based upon 



