i8o 



MORPHOLOG Y. 



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

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



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- 



Fig. 222. 



Male prothallium of fern (niphobolus), showing opened and unopened antheridia ; 39, sec- 

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

 escape from the antheridium. 



