PREFACE 
In the present volume I have endeavored to present 
in as untechnical a manner as seemed feasible the 
more striking facts bearing upon the evolution of plant 
forms. While there are numerous excellent text-books 
in which most of the statements here given are clearly 
presented, there is none, at least in English, so far as I 
am aware, where a connected account of the develop- 
ment of the plant kingdom from an evolutionary stand- 
point has been attempted. Of course every modern 
system of classification is based upon the assumption of 
a genetic connection between the different groups, and 
must take into account the origin of plant forms; but 
these phylogenetic problems are necessarily subordi- 
nated in the general text-books. Moreover, these text- 
books are, for the most part, avowedly prepared for 
the use of botanical students alone. 
It seemed to the writer that an accurate, if some- 
what general, and not strictly technical, statement of 
our present knowledge concerning the data from which 
the genealogical history of the vegetable kingdom may 
be traced, might be of interest not only to such bota- 
nists as have not concerned themselves specially with 
this phase of the science, but also to zodlogists, and 
those general readers who are interested in biological 
problems. 
v 
