The nomenclature question. 
On the application of “once a synonym always a synonym’”’ 
to binomials. 
Reviewing in the March number of the GAZETTE the re- 
cently published ‘‘List of Pteridophyta and Spermatophyta,” 
I made the following statement: ‘‘It will always be possi- 
ble for an erratic botanist to throw together large genera like 
Aster and Erigeron, Bidens and Coreopsis, Panicum and 
Paspalum, thereby displacing [in accordance with the Madi- 
son rules] many specific names which according to the rule of 
once a synonym always a synonym can never be revived.” 
Criticising my position Mr. Coville in the April number of 
this journal pronounces this a lamentable error. Although he 
has quoted my statement accurately he appears to have over- 
looked the important word ‘‘specific,” which it contains, since 
to prove its deplorable inaccuracy he advances merely some 
well-known and wholly irrelevant generalizations regarding 
generic names. Although it should have been clear to every 
Careful reader that the case under discussion had to do with 
Specific names, the point which I wished to make is some- 
what technical and perhaps should have further elaboration. 
When two large genera, like Cacalia and Senecio, or Carduus 
and Cnicus, are united, a certain number of valid species of 
like Specific name are brought under the same generic name 
and a part of them of course must receive new specific names. 
If now the same genera are separated the question of the res- 
toration of the displaced specific names arises at once and 
On this point the Rochester and Madison rules appear to lead 
to a curious dilemma. This can only be made clear by ex- 
ampies. 
Let us suppose that Panicum and Paspalum are united by 
A in 1895 under the former name. As there are at present 
both a Panicum dissitifiorum Steudel (1841) anda Paspalum 
dissitiforum Trinius (1826), it is evident that one must be 
renamed. At Madison it was decided that in such cases it is 
not the age of the combination but the age of the specific 
Name which should be the determining factor, so that the 
@issitiflorum of Trinius would have preference even under 
[261] 
