B. FILICINE^ 



I, Homosporous Type 



NEPHRODIUM FILIX-MAS (The Male Shield Fern) 



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 (palese or ramenta). 



B. The leaves, the most prominent of which are 



i. The fully developed green leaves of the current year : of 

 these 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 



b. 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 repeated bifurcation of 

 the stronger nerves. On the under side of the pinnae will 

 frequently be found 



c. Sori, which are roundish brown groups of small stalked 

 bodies (sporangia), covered by a kidney- shaped indusium. 



