PLAiS^T NOMENCLATURE 259 



person accusioined to the application o£ any iype metliod, can well 

 overlook this obvious fact. And when this fact is clearly understood, 

 such a complex citation as that suggested by Dr. Scliinz, ^^ Mcerua 

 nervosa (Hochst.) Oliver (pro p., ex. syn.) em. Grilg. et Bened.," is 

 utterly absurd. 



8. Oeneric ^^nomina conservanda.^^ — Mr. Sprague's recommenda- 

 tion reads : " All generic names recommended in the future as 'nomina 

 conservanda ' should be accompanied in each case by a summary o£ 

 the generic history, and a statement of the reasons for and against the 

 name." Why the words " in the future " ? The example he gives 

 shows how important the same course is for the names now on the list. 

 If the present list had been prepared in accordance with this 

 suggestion, it would certainly have made a more forceful appeal to 

 the botanical world. 



Lists of " nomina conservanda " are unquestionably at variance 

 with one of the "leading principles" as set forth in the International 

 Kules (Art. 3) : " The rules of nomenclature should neither be 

 arbitrar}^ nor imjjosed by authority." But the trouble is with Art. 8. 

 Are not all rules more or less arbitrary ? And of what value is any 

 rule without tlie force of authority ? This sentence should be cut out 

 of Art. 3, which would then read : " [The rules of nomenclature] must 

 be simple and founded on considerations clear and forcible enough for 

 ever^^one to comprehend and be disposed to accept." This, after all, 

 is the ideal to be pursued. 



Mr. Sprague says that the principle of " nomina conservanda " Is 

 " of a common-sense nature." Perhaps so ; but the application of the 

 principle is a matter upon which even persons of common-sense will 

 tind agreement difficult. Everyone recognized that the presence of 

 the lists seriously weakens the rules, and that such excej^tions should 

 be avoided if possible. 



As the list of "nomina conservanda" for flowering plants now 

 stands, it possesses two very serious weaknesses : one, covered by Mr. 

 Sprague's eighth suggestion, that it does not explain for what group 

 of plants each name is to be conserved (the genera are not typified) ; 

 the other, that the list includes man}^ superfluous names for whose 

 conservation the rules themselves provide. Another weakness is that 

 the list includes many names of genera so small, or so rarely mentioned 

 hitherto in literature, that their importance does not warrant an 

 exception to the rules. Many of the weak spots in the list are due to 

 the way in which it was adopted. Several lists, prepared in advance 

 and before it could be known just what the provisions of the Kules 

 would be, were presented to the Congress, and that of Dr. Harms 

 was adopted in its entirety. Of course, the time available precluded 

 any discussion of individual generic names. 



Mr. Sprague, in his second discussion (Journ. Bot. 1922, 132), 

 calls attention to the fact that the " nomina conservanda " are 

 ^'i\om'ma, ii^fiqice conservanda" or "doivent etre conserves e;i tous casJ" 

 I must confess that I was not convinced that the French and Swiss 

 delegates at Vienna, who emphasized this expression in their dis- 

 cussions, themselves understood just what they meant by it. If Mr. 

 Sprague's interpretation is correct, that it is intended to protect each 



