29C 
A. W. LINDSEY 
for its basis an hypothetical species showing all of the variations 
in question. This might well be regarded as a part of the evi- 
dence furnished by P. napi, but introduces elements not observed 
in that species. 
In this diagram the three circles represent three hypothetical 
cross sections of the species, each of which may be regarded as a 
somatic generation. The central element in each of these may 
represent the basic form of the species, and may, for convenience, 
also be regarded as nimotypical. The axial line through the 
three z elements represents the main line of the germplasm, al- 
though the complete connection of the three generations must 
necessarily be regarded as the cylinder of which they are cross 
sections. That part of the three generations not included in the 
nimotypical form is divided into a geographical race w, a form 
y, and a third element, x, including alternating vernal and aesti- 
val generations. W and x are assumed to show aberrations. In 
the natural state, the probability is that w would produce only 
w, although the available evidence suggests that artificial change 
of environment would lead to the production of each from the 
other. Y and z, occurring in the same region, would be pro- 
duced from each other. As worked out by Verity in P. napi, 
X may represent a definite line. 
Designating the genus as G, trinomial nomenclature would 
name these forms Gzz, Gzx, Gzy and Gzw. In the case of the 
second a puzzling situation presents itself. We have already 
chosen to apply to the entire species the name which has priority. 
If we continue this by assigning to one of the seasonal forms 
priority over the other, a complete designation of the latter in- 
volves the use of a cumbersome, quadrinomial, and any minor 
variation which might receive a name would carry it one step 
further. Another difficulty with such a species is that a thor- 
ough analysis may give us a series of aberrations, such as Gzw 
ab. and Gzy ab., which are distinguished at least in part by the 
same characters and named only upon a basis of their origin. 
This is not common, of course, but in the insects is by no means 
hypothetical. Can it possibly be regarded as necessary for the 
purposes of classification to toil with such a series of names? 
No matter whether such an aberration is among the progeny of 
w, or y, it is the product of the same germ plasm, apparently in 
Reiff, The Lepidopterist i, 15, 1916. Dyar, The Lep. i, 31, 1917. 
