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SOME ASPECTS OF PROGRESS 



IN PLANT MORPHOLOGY 



DURING THE PAST FIFTY YEARS 



Arthur J. Eames 



Fifty years ago as an undergraduate, I was learning about vascular crypto- 

 gams and seed plants and how the herbaceous stem becomes the woody 

 stem. In secondary schools, pupils were studying about "exogens" and "endo- 

 gens" and how to identify the wild flowers. Morphology in this country — as 

 illustrated by the general textbooks of that day — consisted almost entirely of 

 the descriptions of plants and their life histories. Classification was based 

 largely on single characters. Internal structure was seldom mentioned. Com- 

 parative morphology was only beginning to receive attention. 



Progress in the morphological field has been remarkable, even extraordinary, 

 as we look back and try to outline it. Advance has followed many lines: first, 

 the acquisition of much factual material, necessary as a foundation for com- 

 parative interpretations and for the testing of earlier theories and the proposal 

 of new ones; secondly, the development of emphasis on the comparative 

 viewpoint — the use of the more abundant descriptive material for the de- 

 termination of evolutionary progress in form, and thus for the establishment 

 of probable natural relationships. 



The development of comparative study produced new bases for interpreta- 

 tion: the recognition that sound morphology must deal with the entire plant 

 body, with vegetative as well as reproductive parts, with internal as well as 

 external structure; the recognition that simplicity may represent reduction 

 from complexity as well as primitiveness ; that parallel and convergent evolu- 

 tion have played an important part in evolutionary modification ; that evidence 

 of these changes is as often hidden as obvious and must be obtained from as 

 many fields of research as possible — not from morphology alone, but from 

 taxonomy, cytology, genetics, geography, paleobotany, serology, and other 



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