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TEE POPULAR SCIENCE MONTHLY 



with inadequate photosynthetic apparatus would be incapable of sur- 

 vival seems on a priori grounds quite probable. 36 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. 



Diagram 4. Mortality in Sixteen Lots of Typical and Atypical Bean Seedlings. 



Evidence which need not be detailed here pointed to the conclusion 

 that the variegated was the hybrid form, segregating on self-fertiliza- 

 tion 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. Confirma- 

 tory 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 struc- 



Ges., 25: 442-454, 1907. Also, "Die Aurea-Sippe von Antirrhinum majus," 

 Zeitschr. f. Ind. Abst. u. Vererbungsl., 1: 124-125, 1909. Cf. also Bateson, 

 "Mend. Princip. Her.," p. 253, 1909. 



86 De Vries ("The Mutation Theory," I., 229-230, 347-353, 1909; "Species 

 and Varieties," 2d ed., pp. 537-538, 553) finds that albida mutants of CEnothera 

 are very weak — exceedingly difficult to raise when appearing in the seed pan, 

 and never found in nature. 



Among large numbers of bean seedlings which I have grown in the green- 

 house those with white, yellow or variegated primordial leaves have occasionally 

 appeared. It has never been possible to grow these for any considerable time. 



