Page:Popular Science Monthly Volume 84.djvu/144

140 with inadequate photosynthetic apparatus would be incapable of survival seems on a priori grounds quite probable. He found that in the snap dragon, Antirrhinum majus, a variegated or "aurea" form could not be bred true, but on self fertilization gave a progeny of "aurea" and green plants. The inbred green plants produced only green offspring, while the variegated individuals again gave two types of offspring in the ratio of two variegated to one green.

Evidence which need not be detailed here pointed to the conclusion that the variegated was the hybrid form, segregating on self-fertilization according to the simple Mendelian formula into one fourth green, one half variegated (heterozygous) and one fourth lacking chlorophyll—and consequently unfit for survival. Subsequent studies proved that the seeds incapable of forming chlorophyll are actually formed, but that they die in the early stages of germination, or before. Confirmatory results were obtained with a geranium, Pelargonum zonale "verona" where the seedlings lacking chlorophyll died at an early stage.

The preliminary results of a series of investigations on the