60 
Psyche 
[Vol. 90 
bandless females, and that species-specific pheromones need not be 
invoked to account for reproductive isolation. None of Hafernik’s 
females actually mated, but Scott (1972) showed that darkening the 
wings of male coenia does not lower their courting success with 
conspecifics, as it does when females are darkened. 
Despite the consistency of these results, there are possibly con- 
founded variables whenever one tests using entire genomes (as in i 
above, in which pheromonal and subtle behavioral cues cannot be 
controlled for), or altered phenotypes (as in ii and iii, where the 
“similarity” to the other species is questionable, and wing loading 
and odor may be altered by glues or paints). However, another test 
is available, not exploited by Hafernik: pure coenia genomes can be 
induced to produce nigrosuffusa-WkQ phenotypes, which may then 
be presented to coenia males afield. This situation arises from the 
sensitivity of coenia to temperature shocks applied shortly after 
pupation. 
A named aberration of coenia, “schracleri, ” figured in color by 
Comstock (1927, plate 43), resembles nigrosuffusa in lacking the 
band. Other characters, including the hindwing ocelli, are in the 
^ coenia rather than the nigrosuffusa state. Schrader’s specimen was 
reared, but similar individuals do occur in nature. One shown in fig. 
If has the hindwing ocelli and distal pattern obsolescent; others are 
normal for these pattern elements. The actual frequency of bandless 
buckeyes is unknown. 1 have taken two at the same locality in eleven 
years, during which time I must have seen hundreds of thousands of 
individuals. No clear-cut genetic basis for bandlessness has been 
established, but the same phenotypes are readily inducible by 
subjecting wild California pupae to sustained low temperatures. Fig. 
2 shows chilled individuals from three different families. The 
extensive variation in individual response to treatment is character- 
istic of such experiments. The involvement of the ocelli and distal 
pattern is partly controllable by age of the pupa at onset of chilling, 
but even very precise timing can only reduce, not eliminate, the 
variation. Such indeterminacy was characterized as early as 1913 in 
Pictet’s “law of melanization and albinization of parts,” which is a 
statement of the partial independence of different pattern-deter- 
mining processes during wing development. 
Several broods of pure coenia from Solano County, California 
were reared and subjected to a potent cold-shock treatment (3 weeks 
