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hidiana University Studies 
body color from entirely yellow-rufous in the smaller speci- 
mens to darker rufous with some black in the larger speci- 
mens. These larger individuals bear a striking resemblance 
in their wing venation (as far as it is present), body propor- 
tions, and much of their color to the still larger insects which 
are anceps (fig. 337). It is my suggestion that bifurca is the 
result of recent mutation or mutations which have hybridized 
with the parental anceps stocks. If the wing characters are 
actually controlled by multiple factors, we should expect the 
hybrids to form this sort of graded series. The occurrence 
of the colonies of bifurca well within the heart of the range 
of anceps , and the limited extent of these colonies seem indi- 
cators of their comparatively recent origins. Bifurca may be 
an instance of present-day mutation of the sort which, in the 
past, has given rise to the 42 short-winged species of Cynips. 
