288 



FOUNDATIONS OF BOTANY 



FIG. 210. Spore-Plant of a Fern (Aspidium Filix-mas). 



A, part of rootstock and fronds, not quite one-sixth natural size ; fr, young fronds 

 unrolling ; , under side of a pinnule, showing sori, s ; C, section through a 

 sorus at right angles to surface of leaf, showing indusium, i, and sporangia, s ; 

 D, a sporangium discharging spores. (B is not far from natural size. C and 

 D are considerably magnified.) 



