Ferns : Habitats, Life-Story, Morphology 



a spore grows, in the case of ferns, into a little leaflike 

 body (it takes other forms in other plants), which has 

 no resemblance whatever to the adult fern which pro- 

 duced the spore. This prothallium, as we shall now 

 call it, sends roots, or to be strictly accurate, roothairs, 

 into the soil, and takes in food from it and from the 

 atmosphere in much the same way as the ordinary 

 forms of plants procure nourishment from the same 

 sources by means of roots and leaves. On the under- 

 side of the prothallium soon appear little cavities which 

 can only be made out with the help of a microscope. 

 The larger of the small cavities which have been com- 

 pared to flasks, the necks of which project from the 

 surface, while the bottoms are sunk into the substance 

 of the prothallium, are the female organs and corres- 

 pond to the ovaries of the higher plants. These 

 archegonia, as botanists call them, lie generally near the 

 notch on the prothallium, and each one contains one 

 egg-cell which may afterwards grow into a new fern- 

 plant. The smaller cavities, termed "antheridia," which 

 are the male organs, contain little hairlike bodies 

 (spermatozoids or sperms) which work their way out 

 of their chambers, swim to the larger cavities, enter 

 them, and unite with the egg-cells which the latter 

 contain. The egg- cell thus fertilised gives rise to the 

 young fern. Only one egg-cell in each prothallium 

 appears to be fertilised. 



How similar is this process to the fertilisation of the 

 ovules in the ovary of the higher plants by the pollen 



