The Fern Alliance 



there are green cells and stomata on the capsule itself. 

 The spore-plant has therefore an absorbing base, a stalk 

 or stem, and a green capsule with many spores. 



But in the case of the fern alliance, the spore-plant 

 is what we know as the fern, which of course has a 

 well-formed stem, roots, leaves, as well as the spores, 

 which are produced upon the leaves. The spore, 

 which germinates on moist or wet ground, forms a 

 tiny little half-fleshy prothallium about a quarter of an 

 inch long, and it is this that forms spermatozoids and 

 egg cells. 



Professor Bower considers that both ferns and 

 flowering plants have developed from a spore-plant 

 something like that of a moss or liverwort. In very 

 ancient times, the spore-plant developed leaves for the 

 purpose of carrying spores. Then many of these leaves 

 took on the function of foliage leaves and ceased to 

 bear spores. Typical roots developed from the base of 

 such a spore-plant, and it also formed internodes between 

 the leaf bases just as and when required.* 



In the flowering plants the sperm cell (part of the 

 pollen grain) is carried either by wind, insects, or some 

 other means to another flower ; but when the pollen- 

 tube begins to grow down into the style so as to reach 

 the egg cell, there are certain faint indications which 

 seem to remind us that at some very ancient and dis- 

 tant period it was a free-swimming, spirally curved 

 sperm cell, perhaps like that of a fern. 



There are a few cell divisions during the develop- 

 ment of both the pollen grain and egg cell which seem 

 to correspond to the prothaUium. 



* There are the three theories, (i) The leaf preceded the stem. (2) Leaf 

 and stem appeared together. (3) The stem preceded the leaf. The reader must 

 be referred to the original for further details as to Celakovsky's Sprossglied 

 theory, &c. When put in brief the discussion sounds as futile as, Which 

 came first, the hen or the egg ? 



85 



