TAXONOMY OF THE HIGHER PLANTS 203 



plants and that stability of names was essential if that key was not to become 

 the weak link in the communication chain. 



Along with all of science and the world of learning, there has always been 

 a strong desire in botany to recognize the work of the pioneers and to give 

 credit to original discovery. Thus the principle of priority was settled upon 

 as the basis for determining which of the competing names was to be accepted 

 for a given taxon. Priority of publication has worked well when applied to 

 most fields of learning, and some sense of justice has dominated the recog- 

 nition given to the discoverers of the laws and principles of each discipline. 

 This is in general true despite attempts to alter priority considerations by 

 nationalistic propaganda. However, the application of priority to discovery 

 involving a relatively few items such as facts, laws, principles, geographical 

 areas, and the like is not overly complex. On the other hand, applying priority 

 to the names of organisms, where discovery is at a relatively high rate and 

 the total number is great, is far more difficult and complex. 



A real complication arises from applying strict priority because many 

 names, especially those of Old World plants, had an obscure beginning. 

 Nevertheless, there was a movement in the late eighteen hundreds and the 

 early part of the present century, led by certain American and German bota- 

 nists, to make absolute priority the basis for the application of plant names. 

 The utter impossibility of untangling the dates of sixteenth-, seventeenth-, and 

 early eighteenth-century literature, or even finding much of it, was early 

 recognized. As a result, limited priority has been adopted as a working 

 principle and agreements have been reached on starting dates before which 

 priority is not operative. 



Out of such problems of communication, involving as they do truly inter- 

 national questions, international congresses of botany have developed an 

 International Code of Botanical Nomenclature, which is now universally 

 accepted. All the work of international cooperation along these lines has not 

 been done, but great strides in this direction have been made during the 

 last half century. The earlier attempts of a small group of American botanists 

 to establish an American Code of Botanical Nomenclature were doomed to 

 failure because strictly nationalistic actions seldom prevail in matters of 

 universal concern. Fortunately, through compromise, all botanists have been 

 won over to the support of the International Code, which combines many 

 of the best features of both previous codes. Competing codes of nomenclature 

 have thus been eliminated. 



Taxonomists have developed a unique technique of communication that is 

 of some importance, though not generally known outside of the field. I refer 

 to the use of sets of exsiccatae. The procedure is to collect a number of 

 specimens of a single species at a single location. This set of exsiccatae is 

 then studied in conjunction with other material of the species it represents. 

 When finally labeled and distributed, these specimens provide a roughly com- 



