520 PLANT GROWTH AND PLANT COMMUNITIES 



in unrelated groups, it may be inferred that the underlying genetical 

 changes were those which had a high probabiHty of taking place and 

 of yielding floral constructions with a high survival value. 



In considering the extensive, conspicuous, and often confusing 

 diversification that inflorescences and flowers have undergone during 

 the course of evolution, it now appears, on the evidence and arguments 

 outlined here, that only a comparatively small number of major growth 

 and organogenic changes, in which both genetical and non-genetical 

 factors participate, may have been involved. If this view can be vali- 

 dated by critical investigations along the lines that have been indi- 

 cated, the hope may well be entertained that this complex mass of 

 biological materials may eventually be understood and described in 

 terms of simplifying and unifying concepts. 



Conclusion 



Before the word "scientist" was coined and had come into com- 

 mon usage, investigators of natural phenomena, who usually had other 

 scholarly attainments, were described as natural philosophers. It is still 

 important that biological science should have a philosophical content, 

 the central feature of which should surely be an attempt to arrive at a 

 true understanding of living organisms as organisms, in all their diver- 

 sity, both ontogenetic and phylogenetic. As a working procedure, the 

 attempt to describe the processes in living organisms in terms of mathe- 

 matics, physics, and chemistry not only has many merits but is indeed 

 essential. But, in the writer's view, it is unlikely to succeed without the 

 elaboration of further concepts— those relating to the specific organiza- 

 tion which is passed on from generation to generation and which is 

 characteristic of all living things. The biologist who accepts this view 

 need never fear, as some of our contemporaries do, that biology will 

 pass out of his hands into those of the biophysicist and biochemist. The 

 study of floral morphogenesis, concerned as it is with the most elaborate 

 organs in the most highly evolved and numerically largest group of 

 organisms in the plant kingdom, aflFords a superabundance of materials 

 to excite man's curiosity and challenge his capacity for investigation 

 and philosophic reflection, leading eventually, we may hope, to the 

 enunciation of simplifying general truths. 



Summary 



The need for comprehensive morphogenetic investigations of an- 

 giosperm inflorescences and flowers has here been emphasized. Such 

 work is likely to advance our knowledge both of causality and phy- 

 logeny. The investigations envisaged also hold out the hope that some 



