582 CONSTANCE 



advantages over bricks because, first, they would be readily movable from 

 any given position to a more logical and advantageous one. Secondly, each 

 pamphlet box could be a repository for every scrap of information contributed 

 by workers in diverse fields. Thirdly, the system could easily be made three- 

 dimensional when this seemed desirable. Hence, by our analogy, we achieve an 

 open, growing, vital taxonomic system in place of the closed, static, and 

 dormant one that we are sometimes accused of cherishing. You will note that I 

 have succeeded in substituting three ''good" words for three "bad" ones! 



If the concept of an open, information-thirsty taxonomy has any merit, 

 let us note the different kinds of data it has been absorbing since 1906 and 

 what effect these accretions have had upon the current status of plant taxon- 

 omy. 



Obviously, the first increment of data in our file boxes, as well as the prime 

 factor governing their initial arrangement in the bookcases, was contributed 

 by morphology. Because structure was the first basis for any real classi- 

 fication, it is usually indissolubly linked with taxonomy in the minds even of 

 taxonomists. Likewise, because it was highly developed before evolutionary 

 theory came into the picture in any significant way, it is sometimes viewed, 

 like taxonomy, as essentially descriptive, only semi-scientific, and even as 

 exerting a drag on progress in systematics. The taxonomist, having no suit- 

 able substitute for laying out the warp and woof of his various arrangements, 

 has perhaps been preoccupied with form, even to the extent of feeling that 

 other criteria are non-essential, or at least of distinctly inferior merit. The 

 fact that recorded observations on morphology have been sufficiently numer- 

 ous and extensive to provide some systematic purview of this aspect has made 

 it of unique importance to classifiers. My colleague. Professor Mason, has 

 wisely noted (1950) that abundant, systematized, comparative data are es- 

 sential in any field before such information can be employed satisfactorily 

 for purposes of classification. 



Comparative morphological evidence has been accumulating at least since 

 the time of Theophrastus, the Herbalists made extensive contributions, and all 

 systems with which I am familiar are primarily morphological in basic con- 

 tent. I should venture the guess, also, that they will continue to be for the 

 foreseeable future. In his excellent monograph on the genus Crepis (1947) 

 Babcock clearly indicated the dependence of the cytologist and geneticist 

 upon morphological taxonomy for the organization and interpretation of their 

 data. In recent decades, however, the central if not exclusive preoccupation 

 with flower and fruit in classification has yielded to a growing recognition of 

 the taxonomic importance of other organs and structures, as well. 



The morphology accepted and employed for his classifications by the 

 systematist, as you are aware, was classical morphology, with its emphasis 

 on the existence of discrete fundamental organs and their presumably un- 

 alterable relationships. These once generally accepted canons have been under 



