A New Proof of the Lefschetz Formula on Invariant Points.

the flower colors in the resulting progenies, while in the second type of cross it is the Ss factors whose segregations determine the flower colors of the families produced. The Ss factors are in linkage group I in which the rubricalyx factor is also included, while the Vv factors are in linkagegroup III. It is clear, therefore, that independence between old-gold and rubricalyx can be observed whenever the Vv factors alone are segregating and the SS factors remain constant; whereas, a close linkage may be observed between old-gold and rubricalyx, or other first-chromosome factors, when it is the Ss pair that is segregating and the vv factors remain constant.