18 
‘ alternation of generations’. This is represented 
in a graphic manner below :— 
PROTHALLUS 
(Sexual Plant) 
Archegonium Antheridium 
| Spore 
Egg-cell Sperm 
Sporangium 
Fertilized ' 
Egg-cell 
Fern Plant 
» (Asexual Plant) 
4. VEGETATIVE REPRODUCTION 
Besides the sexual reproduction illustrated 
in the life-history described above, many ferns 
are capable of reproducing themselves vegeta- 
tively. Thus the fronds of Adiantum cauda- 
