THE FERN BULLETIN 



7 



curing a plentiful supply of food, it may develop only 

 antheridia, but if well nourished, archegonia may be- 

 gin to appear a short time after the antheridia, and 

 upon the same side of the prothallium. The two kinds 

 of organs are rarely, if ever, intermingled, the arche- 

 gonia always appearing on the younger parts, near 



Anth. 



Gametophitk of the Fern. 

 A— The antheridium containing sperms. B— The archegonium. C— The sperms. 

 D -A very young prothallium. sp.— The spore. All much enlarged. 



the notch which gives the heart-shaped outline to the 

 gametophyte. 



The archegonia, like the antheridia consist of sev- 

 eral cells and in the base of each is developed a single 

 cell called the egg. When the egg is mature, the cen- 

 tral cells in the neck of the archegonium break down 

 and disappear, leaving a channel from the outside 



