4 INTRODUCTION. 



and spiritual grace" if one maybe allowed the quotation that 

 no one need be guilty of the solecism involved in speaking of 

 ferns in terms of flowering plants, and vice versa. 



A flowering plant, whether its flowers be showy or incon- 

 spicuous, produces its blossoms as a necessary stage in the pro- 

 duction of fertile seeds. Each seed contains within its several 

 wraps what is essentially a detached bud, including root, stem, 

 and leaves in embryo ; and only requires to be placed under 

 suitable conditions of warmth and moisture, when it will germi- 

 nate or begin to grow into a plant that differs from its parent 

 only in the matter of size. To produce that seed it was neces- 

 sary that the grains of protoplasm (pollen} produced in the 

 anthers of the flower should mingle with those (ovules) produced 

 in the ovary the ordinary process of fertilization common 

 throughout both animal and vegetable series of organisms. 

 The cardinal point in the differences between flowering plants 

 and ferns is that the latter do not produce seeds, or detached 

 buds, directly, so there is no need for flowers. 



How, then, is the succession kept up? How does each 

 species continue to exist, generation succeeding generation ? 



This important matter is very fully provided for by an 

 analogous process ; but it is not performed in immediate con- 

 nection with the fern as we all know it. There is a phenomenon 

 known to naturalists as the " alternation of generations," and it 

 prevails throughout the various families of ferns. Of four suc- 

 cessive generations of fern-life, generations i and 3, though 

 agreeing each with the other, will differ widely from genera- 

 tions 2 and 4, though they are all in the direct line of descent 

 one from another. It is not an easy task to make this matter 

 plain to those who are not botanists, but as a clear under- 

 standing of it is essential to a proper appreciation of the 



