The Sporing of the Fern 257 



of the prothallus is expended in nourishing the 

 oospore. Sometimes it so happens that several 

 sister oospores are ready to grow at the same 

 time. But generally in this case one dominates 

 the rest in the great struggle for life, and draws 

 into itself all the nutriment which the prothallus 

 can bestow. And so a prothallus seldom gives 

 rise to more than one little fern. 



If a prothallus is insufficiently nourished it may 

 bear antheridia only, and no archegionia at all. 

 Such " male" prothalli are apt to develop after an 

 eccentric fashion of their own. They are often long 

 and narrow, sometimes almost filamentous in form 

 and grow into irregular projections. In fact, they 

 are sometimes <4 all bubukles, whelks, and knobs," 

 like BardoJph's countenance. 



They are relatively small, and may even be 

 reduced to a single vegetative cell, an antheridium, 

 and a few root-hairs. 



Several common native ferns, notably the great 

 Osmundas, always give origin to a number of starve- 

 ling " male " prothalli, in addition to the larger and 

 more symmetrical ones which bear both antheridia 

 and archegonia. 



And in a few flowerless aquatic plants, closely 

 akin to ferns, all the prothalli are either male or 



