2130 A TEXTBOOK OF THEORETICAL BOTANY 



systematics there are two distinct aims and two distinct approaches. 

 Linnaeus said that the Natural System was the Alpha and Omega of 

 Systematic Botany and the fashion has grown up of using these tw^o terms 

 to symbolize the two different aspects. 



This then is the working solution of the dilemma which has been arrived 

 at, namely to separate Alpha Taxonomy, which is the classical subject, 

 logical and orderly in intent and chiefly morphological in method; a worthy 

 Martha, domestic, even rather urban in outlook; from its younger sister 

 Omega Taxonomy, a Mary in country clothes, with the highest aspirations 

 but with uncombed hair and something of the wildness of Nature still in 

 her heart. Alpha Taxonomy is indispensable. We must wed her and 

 cherish her, while Omega Taxonomy, which promises to unlock for us the 

 secrets of the Natural System, intrigues our romantic imagination. Nor are 

 the two interests incompatible. Alpha leads the way to Omega. As Vavilov 

 has said, the recognition of the Linnean species is the first step in biological 

 knowledge and without that as a foundation the fuller exploration of 

 systematics would not be possible. Linnaeus himself knew this and we 

 may sum up the situation in his own words: "Artificial orders serve to 

 distinguish one plant from another, natural orders serve to teach the nature 

 of plants." 



The principle of grouping which has been adopted in the systematic 

 chapters of the present work demands a word of explanation. The tendency 

 of recent classifications of particular groups has been predominantly 

 analytical. This viewpoint may be expressed by the question, " Is there 

 sufiicient difference between A and B to justify their separation into different 

 groups?" The replies of the specialist to this question are increasingly in 

 the affirmative, so that a great multiplication of families and orders has 

 consequently taken place. This is to be expected. It is a movement from 

 Alpha towards Omega, but if it obscures and distorts the more practicable 

 Alpha systems it is dangerous and undesirable. On the other hand the 

 writer of a textbook is faced with the pedagogical problem of presenting a 

 synthetic outline, not of a particular group, but of all groups, and he is 

 obliged to react differently. He must keep to the Alpha line. His leading 

 question must be, " What are the largest units which are scientifically per- 

 missible? " and he has to approach the classifications of the specialist with 

 this in his mind. The outcome, like all compromises, is naturally open to 

 criticism. The authors are prepared for this in regard to their own particular 

 solution but wish to explain that their attempt to modify the angularities 

 of specialist classifications has been based upon the conviction that it is 

 more important, in the earlier stages of study, to recognize and emphasize 

 similarities, rather than meticulously to discriminate differences. 



With the exception of Thallophyta the limits and positions of the main 

 Phyla of the Plant Kingdom are now generally recognized, though the 

 position of the Charophyta is still uncertain. On the other hand, the 

 Thallophyta have proved an unsatisfactory group, and many authorities 



