266 



MORPHOLOGY. 



of pots in conservatories, mount it in water on a slip, with 

 the under side uppermost, we can then examine it for the 



Fig. 304- 

 Male prothallium nf a fern (niphobolus), in form of an alga or protonema. Spermato- 

 zoids escaping from antheridia. 



sexual organs, for these are borne in most cases on the under 

 side. 



556. Antheridia. — If we search among the rhizoids we see 

 small rounded elevations as shown in fig. 297 or 305 scat- 



Fig. 301;. 



Male prolhaJlium of fern (niplioboliis), showing opened and unopened antheridia, section 

 of unopened antheridium ; spermatozolda escaping; sperniatozoids wliich did n:ct escape 

 from the antheridium. 



