210 ENTOMOLOGY 
“So firmly have these characters become ingrained in the 
tracheate series, and so important is this relation of the hard- 
ening of the cuticula to the musculature and to the formation 
of body sclerites, that even the most specialized forms show 
this primitive system of coloration; and, although there may 
be spots and markings which have no connection with it, still 
the chief color areas are thus closely associated.” 
Development of Color Patterns.— Although the causes of 
coloration are, for the most part, obscure, it is possible, never- 
theless, to point out certain paths along which coloration ap- 
pears to have developed. These paths have been determined 
by the comparison of color patterns in kindred groups of in- 
sects and the study of colorational variations in adults of the 
same species. The development of coloration in the individ- 
ual, however, has as yet received but little attention—excepting 
the excellent studies of Mayer and of Tower. Butterflies, 
moths and beetles have naturally been preferred by most stu- 
dents of the subject. 
The most primitive colors among moths are uniform dull 
yellows, browns and drabs—the same colors that the pupal 
blood assumes when it is dried in the air. These simple col- 
ors prevail on the hind wings of most moths and on the less 
exposed parts of the wings of highly colored butterflies. The 
hind wings of moths are, as a rule, more primitively colored 
than the front ones because, as Scudder says, “all differen- 
tiation in coloring has been greatly retarded by their ‘almost 
universal concealment by day beneath the overlapping front 
wings.’ Exceptions to this statement are found in Geomet- 
ridee and such other moths ag rest with all the wings spread. 
“Tn such hind wings we find that the simplest departure from 
uniformity consists ina deepening of the tint next the outer mar- 
gin of the wing; next we have an intensification of the deeper 
tint along a line parallel to the margin; it is but a step from this 
condition to a distinct line or band of dark color parallel to 
the margin. Or the marginal shade may, in a similar way, 
break up into two or more transverse and parallel submarginal 
