FERNS. 



S53 



The secondary divisions (or first divisions of the pinnje) are the 

 pinnules. The stem, as in the Polypody, and in fact in all our 

 Ferns which have a stem at all, is a rootstock or rhizome. But 

 here we miss the fruit-dots or sori, so conspicuous in our first 



example. In this case it will be found that 



there is a continuous line 0/ sporangia around 

 the margin of every one of the pinnules of 

 the frond, and that the edge of the pinnule 

 is reflexed so as to 

 cover the line of spore- 

 cases. Fig. 263 is a 

 very much magnified 

 view of one of the 

 lobes of a pinnule, 



Fig. 26a 



Pig. 262. 

 mth the edge rolled back to show the sporangia. Some of the 

 sporangia are removed to .show a line which runs across the ends 

 af the forkincr veins. To this the sporangia ai-e attached. The 

 reins, it will he seen, do not form a net-work, and so are free, as 



