REPRODUCTION 



81 



is rounded and it has an outer wall composed of one layer of 

 cells. The inner cells develop into sperms. The sperms of the 

 ferns are multiciliate coiled cells. The archegonia grow on 

 the under surface of the prothallus just back of the heart- 



FIG. 44. Filicales. Eight figures showing the developing sporophyte and the 



disappearance of the gametophyte after the formation of four fronds,. 

 6 



