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 



ijj// 



Fig. 221. 



Male prothallium of a fern (niphobolusj, 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 see 

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



Fig. 222. 



Male prothallium of fern (niphobolus), showing opened and unopened antheridia ■ section 

 of unopened antlieridmni ; spermalozoids escaping ; sperjnatozoids which did not escaoe 



from the antheridium 



which did not escape 



