16 



Each archegonium is flask-shaped and contains 

 in its lower swollen portion a single female 

 sexual cell the ovum or egg-cell (Es.). 



The sperm is a long spirally coiled body, 

 blunt behind and tapering to a point in front 

 where it bears fine hair-like processes termed 

 cilia, by the vibratile movements of which it 

 moves about in the water which saturates the 

 soil in which the prothalli are growing. Sooner 

 or later it comes into the neighbourhood of an 

 archegonium, being attracted to it by the 

 mucilaginous exudations from the neck. It 

 enters the archegonium by the neck and 

 fuses with the egg-cell. Thus fertilization is 

 accomplished. 



From the fertilized egg-cell, what is com- 

 monly known as the ' Fern Plant ' is produced. 

 This is at first extremely small and grows at 

 the expense of the food-material supplied by 

 the prothallus to which it remains attached till 

 it is able to spread its own roots and live 

 independently. (Fig. 5.) 



From what has been said above it will be 

 evident that there are two stages or phases in 

 the life-history of the Fern : -(i) The short- 

 lived prothallus which grows from the spore 

 and bears the sexual cells, and (2) the ' Fern 



