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University of California Publications in Agricultural Sciences [Vol. 2 



toward the midrib. It occurs in both entire and pinnatifid types, 

 thoiigrh it is more conspicuous in the former. In appearance much 

 like the funifolia mutant of Oenothera Lamarckiana described by 

 ShuU (1921), in which both rosette and cauline leaves have edges 

 curled under. The knowledge of the genetic basis for this character 

 has been obtained incidentally in experiments designed to show in- 

 heritance of other characters. The data thus obtained indicate that 

 revoluteness is conditioned by complementary recessive genes. 



TABLE 8 

 Showing the Segregation of Revo lute Leaves in Two Cultures 



Tt is significant that revolute appeared only in these two cultures, 

 which were derived from a common source, because it indicates that 

 the genes were present in the wild plants from which the starting point 

 of these cultures was obtained. The 15 to 1 ratio made its appearance 

 in the sixth generation from the wild plants (some out-crossing occurs 

 in this pedigree), while the 3 to 1 ratio appeared in the second gen- 

 eration. 



BICEPHALIC (bi) 

 Plate 48, figure 1 

 This character designates a type of fasciation in which the buds 

 are more or less joined together in twos. The peduncle is also fre- 

 quently flattened. This variation was first found in 1920 on a single 

 plant (20.30) which was grown from achenes obtained from Chile. 

 This original plant was crossed with 20.130Pi„, which produced an 

 Fi culture of 9 normal plants. The Fo, consisting of 81 plants, segre- 

 gated into 60 normal to 21 bicephalic, clearly a monofactorial ratio. 



