34 



FRIEDA COBB 



TABLE 15 

 Analysis of the FI generation of the cross mut.formosa X /. typica M (heterozygous] (a'@ff X 



In the case of 41, the staminate parent belonged to the F 2 generation of the cross mut. for- 

 mosa X mut. latifolia C; in the case of 42 and 43 to the F 2 generation of the cross mut. formosa 

 X hyb. viscida. 15 In each of the cultures flat-leaved and revolute-leaved plants occur, in about 

 equal numbers. The expected ratio is 1:1. When the germination is poor, the number of 

 revolute-leaved plants often slightly exceeds the expectation, as it does here. Of the 42 plants 

 grown to maturity, taken in part from each of the three cultures, 21 were f. typica (one of them 

 a 'dwarf), 3 were of other flat-leaved types (2 of mut. graminea, 16 and 1 an undetermined muta- 

 tion), 16 were mut. formosa (6 of them very poor plants) and 2 were mut. revoluta, which is one 

 of the revolute-leaved mutations thrown by mut. formosa. 



TABLE 16 



Analysis of an FZ progeny resulting from self-pollination of an f. typica plant of the FI 

 (see table 15} of the cross mut.formosa X /. typica M (heterozygous} (a'fiff X a'pFf). 

 bers of flat-leaved and revolute-leaved plants closely approximate a 3:1 ratio. 



generation 

 The num- 



TABLE 17 

 Analysis of the F\ generation of the cross f. typica M (heterozygous] X mut.formosa (a'fiFf X oi' 



The pistillate parent belonged to the F 2 generation of the cross mut. formosa X mut. lati- 

 folia C. In these cultures flat-leaved and revolute-leaved plants occur in about equal numbers, 

 but, as in the reciprocal cross, the number of revolute-leaved plants slightly exceeds that required 

 for the expected 1 : 1 ratio. Of the 88 plants grown to maturity, taken in part from each of the 

 two cultures, 36 were f. typica, 2 were of other flat-leaved types (1 of mut. ericacea 17 and 1 dwarf), 

 and 50 were mut. formosa, one of them bearing a flat-leaved bud-sport. 



15 Hyb. viscida, a hybrid of Oenothera pratincola X Oe. numismatica (see BARTLETT 1915 a, 

 p. 86). This form is like Oe. pratincola L typica with the addition of the viscid pubescence 

 of Oe. numismatica. 



16 Regarding mut. graminea, see BARTLETT 1915 b, p. 429. 



17 An undescribed mutation. 



