i8o 



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. 22T. 



Male prothallium of 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. 



372. Antheridia. — If we search among the rhizoids we will 

 see small rounded elevations as shown in fig. 214 or 222 scat- 



Male prothallium of fern (niphobolus), showing opened and unopened antheridia ; 30,, sec- 

 tion of unopened anthertdium; 40, spermatozoids escaping ; 41, spermatozoids which did not 

 escape from the antheridium. 



