Unchanged from progenitor
viable
visible | dominant
eye
Phenotype less extreme than that of B1. Bi male has 478 facets, Bi/Bi has 320, and Bi/+ has 716.
Facet development inversely proportional to temperature; effective period for temperature treatment is 60% through larval life or about 60 hr at 25oC.
RK1A.
Sturtevant, 1923.