14 Beiblatt zu den Botanischen Jahrbüchern. Nr. 52. 
ruling lies in the practical stability to be derived from it. For in nearly all 
cases the first correet combination can be definitely ascertained. On the 
other hand, if there is any departure from this principle and any attempt 
to combine earlier specifie names with those of the accepted genera, there 
must be a lasting doubt as to the validity of nearly all post-linn:ean specific 
names. For very few of them can be so securely established that they will 
be free from constant danger of being displaced by the discovery, in some 
obscure work, of slightly older names used perhaps under remote genera. 
Added to this inherent lack of stability the unqualified adoption of the first 
specific name leads to indefiniteness through the constant endeavor to base 
our nomenclature upon more and more remote, fragmentary, and obscure 
descriptions of the past, such as those of Rafinesque, while in general the 
first eorrect combinations, having been formed in more recent times when 
generic and speilie limits were better understood, have been based upon 
or accompanied by fuller descriptions, forming a much sounder foundation 
for nomenclature. For these reason it seems best to adopt the principle of 
priority under the genus, the whole question of determining in individual 
cases the proper scientific name being thus greatly simplified, since all 
competing names are under the same generic designation. It is to be em- 
phasized, however, that this ruling does not lessen the obligation of botanists 
of the present and future in making a transfer of a species from one genus 
to another to preserve serupulously the specific name without alteration, 
except in the case of an existing homonym. 
4. The varietal name is to be regarded as inferior in rank to the spe- 
cific. The variety is the least definite category of classification, and varietal 
names have not only been treated with much greater laxity than the spe- 
cific, but are generally unindexed, so that it would be a work of years to 
collate them. To bring them (as advocated by certain recent works) into 
active competition with specific names would thus tend immeasurable to 
increase the difficulties of an ultimate settlement of specifie nomenclature. 
The rule that à variety may not hold the same name as a species in the 
same genus is highly arbitrary, and would lead not only to the renaming 
of thousands of varieties, but the practical impossibility uf using in large 
genera like Aster, Solidago, Senecio, Solanum, and Carex any telling 
descriptive names for varieties, since all such have long since been used 
for species. 
No specific name should be altered, because of preexisting varietal 
names for the same plant. Nevertheless, it is recommended as a working 
rule that whenever a variety is raised to specific or a species depressed to 
varietal rank the name should be preserved whenever possible. 
5. The principle of »onee a synonym always a synonym«, while recom- 
mended as an excellent working rule for present and future, may not 
Justly be made retroactive. 
