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THE AMERICAN NATURALIST [Vol. XL VII 



The second part of my study of this family concerned 

 the behavior in the F 3 of a plant representative of the 

 mass of the F 2 generation. The individual chosen, 

 11.41c (Davis, '12a, p. 412), was a large plant (Fig. 3) 

 with long branches from the base and a foliage of con- 

 spicuously crinkled leaves. The type was represented 

 by about 170 plants in the culture and, intergrading with 

 other forms, stood close to the center around which the 

 mass of the culture varied. This plant, 11.41c, was sim- 

 ilar to the F x parent hybrid, 10.30La, except that it 

 showed something of the general progressive advance 

 throughout the F 2 generation in the broader and more 

 crinkled leaves and in the somewhat larger flowers 

 (petals 2.5 cm. long). 



From the plant 11.41c an F 3 generation was grown 

 (culture 12.52). There were sown 411 seeds, the contents 

 of 3 selfed capsules and 285 rosettes developed. Among 

 the seedlings 18 plants at once caught my attention as 

 having etiolated leaves following the cotyledons. These 

 18 seedlings developed into small rosettes with narrow, 

 strongly etiolated leaves, which could not be distin- 

 guished from the etiolated dwarfs that have been de- 

 scribed above. The contrast between the green rosettes 

 of this culture, 12.52, and these etiolated dwarfs, is 

 illustrated in Fig. 4, which shows sister plants, 12.52a 

 green and representative of the mass of the culture, and 

 12.52ra one of the 18 etiolated dwarf types. By the side 

 of 12.52ra, for comparison (see Fig. 4), is shown one of 

 the 48 etiolated dwarfs in culture 12.53, which, although 

 an F 3 individual from 11.41m, illustrates accurately the 

 appearance of the etiolated dwarfs in the F 2 generation. 

 It will be noted that the two dwarfs, 12.52ra and 12.53a, 

 are of the same type. 



The 18 etiolated rosettes of the F 3 culture 12.52 grew 

 into dwarfs indistinguishable in all essentials from the 

 48 plants of the F 8 generation 12.53 and the 141 plants in 

 the F 2 represented by 11.41ra (Figs. 1 and 2) . They out- 

 grew the etiolated condition of the younger stage, but re- 



