SOME PROBLEMS OF TAXONOMY 
297 
response to the same stimuli, and as such may be designated by 
reference directly to the nimotypical form with at least suf- 
ficient minuteness for ordinary use. For genetic considerations 
these minor forms may be treated without naming, as will be 
mentioned later. We should note, before leaving this matter, 
that in most cases such divisions as have been discussed are 
based upon differences of color and pattern, which are apparently 
quite directly responsive to changes of environmental condi- 
tions. When lines such as w, x and y occur, their existence is 
probably due to slight normal differences of environment, and 
we must recognize that the fiuctuaticns of meteorological con- 
ditions might easily result in temporary similarity of these nor- 
mally different conditions of existence, such as would produce 
forms and aberrations like those under discussion.^® If the simi- 
larity of these is complete, they may certainly be named as one ; if 
partial, as in the case of the Catocala arnica forms mentioned in 
the paper last referred to,^® they are certainly not worth sepa- 
rating from their parent forms. 
The problem presented by this type of variation, involving 
only a moderate number of forms in any species, and these 
fairly well marked, is comparatively simple. It is essential, in 
the first place, to have a name which may be applied definitely 
to the entire species, and there is no serious objection to the rule 
of priority now applied. In a few cases, as Papilio glaucus Linn., 
a subordinate form has priority. When, as in this case, the 
nimotypical form occurs in only one sex, the necessity for modi- 
fication is strongly suggested, but the simple application of tri- 
nomial nomenclature is an ample measure. 
With regard to the use of polynomials to indicate the com- 
plete relationship of the ultimate division with the nimotypical 
form, personal opinion must enter. As matters stand at pres- 
ent this unavoidably leads to cumbersome combinations. Neither 
modern system of nomenclature eliminates these, yet these sys- 
tems have points of value which we should be reluctant to sacri- 
fice. If the pronounced tendency were not present among ento- 
mologists — I feel inclined to say lepidopterists in particular — to 
In dealing with such superficial characters as distinguish most minor 
forms and aberrations, the question of reversal can hardly enter. More 
fundamental modifications such as would involve this question do not, in 
any case known to the writer, furnish the basis for such a complexity of 
nomenclature as is here discussed. 
