PREFACE XI 
courses. The presentation should be made as simple as 
possible, consistent with the realization of these aims. 
From the standpoint of pure science, the most funda- 
mental problem of botany is that of the development of 
the individual plant; the ultimate problem that of the 
development of the kingdom of plants. In other words 
the foundation and the ultimate goal are, respectively, 
ontogeny (life-history of the individual) and phylogeny 
(life-history of the race). 
Ontogeny is fundamental because without a knowledge 
of its processes the processes of phylogeny cannot be com- 
prehended. Phylogeny is the ultimate problem because 
its complete solution involves an orderly description of all 
the phenomena of plant life, and their relation to each 
other. 
Thanks to the nature-study movement, most students 
have nowadays acquired some knowledge of the parts and 
a few of the functions of a flowering plant before they take 
up the study of formal botany; for such, Chapter II will 
serve only as a timely review; for others, as an essential 
preparation for the subsequent chapters of Part I. 
From an educational point of view, the most rapid 
progress and the most substantial results are to be ob- 
tained by an order of topics so arranged that each will 
throw the greatest amount of light on those that follow. 
It is also an immense gain for the pupil to be introduced 
to the broad generalizations of the science by being led 
to meet them for the first time in that type where their 
concrete embodiment is most clearly defined and most 
easily discerned. In the author's mind, acceptance of 
these two postulates points unmistakably to the fern as, 
par excellence, the best plant with which to begin the study 
