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 Hfe, 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 generahzations 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 



