FILICALES 



327 



the one diploid (non-sexual), which is the sporophyte, the other 

 haploid (sexual), which is the gametophyte. The former is what is 



FIG. 266. 



Nephrodiutn Filix-mas, Rich. Fertile leaf about one-sixth natural size, the lower 

 part with the under surface exposed. To the left a single fertile segment, bearing 

 kidney-shaped sori, enlarged about seven times. (After Luerssen.) 



known commonly as the Fern-Plant; the latter is a small green 

 scale-like body, which is called the Prothallus. Naturally, as the 

 former is the better-known phase, it will be described first. 



MALE FERN AND BRACKEN 



The large-leaved shoot of the Fern Plant may grow upright, and 

 usually unbranched, as in Tree-Ferns, and the Royal Fern (Osmunda) ; 



