Mathan. D.
Heterozygous lanceolate (La/La^+) has a simple entire leaf and frequently up to two reduced lanceolate leaflets on the petiole (TGC6:19,1956). When the F1 lanceolate plants of the cross lanceolate (e^+/e^+ La/La^+) x broad (e/e La^+/La^+) were backcrossed to the lanceolate parent, the backcross progeny segregated, 1 normal : 2 lanceolate : 1 narrow, an extreme lanceolate type. Narrow plants, which were compiletely sterile, were assumed to be the homozygous lanceolate.
In the early experiments, the original lanceolate line segregated 1 normal : 2 lanceolate, but about 1/4 of the seeds failed to germinate. Hence it was assumed that the homozygous lanceolate was completely lethal in this particular line. However, when seeds of heterozygous lanceolate were placed on a moist filter paper in a petri dish and left in the dark, all of them germinated. The seedlings segregated 1 normal : 2 lanceolate : 1 reduced. The latter type, which was assumed to be homozygous lanceolate, never developed beyond a cylindrical mass of green tissue about 5 cm. tall and 0.2 cm. in diameter. There was no trace of cotyledons or plumule.