5. Virescent‑19.

This virescent appears to be rather widespread among genetic stocks. It has turned up in the stock of glossy₅, in some of Dr. Roman's stocks of B chromosome translocations, and in several other cultures of mixed ancestry all involving recent crosses to Cornell genetic stock. These items all suggest that the source may be some early stock widely used by Dr. Emerson and his students and co‑workers at the time much of the genetic stock material was being built. As a genetic marker, v₁₉ is fairly good in greenhouse seedling tests, but greens up too readily to be classified in the field under our conditions. Where specific seedling chlorophyll notes are not being taken, it cculd be tided along indefinitely in stocks used for other purposes.

E. E. Dale and E. G. Anderson