MENDELIAN INHERITANCE IN OENOTHERA PRATINCOLA 9 



the seed-pans, and possibly revolute-leaved plants, which do not hold their 

 own in a dense stand, died before the seedlings were counted off. This, 

 however, does not seem likely, and the matter will be further investigated. 



The reciprocal cross, f . typica M (homozygous) X f. typica E (a'fiFF X 

 aftff), gave in the FI generation (see table 21) only flat-leaved plants 

 (a'fiFf) and in the F 2 generation (see table 22) a segregation of 3 flat-leaved 

 plants (a'fiFF and cf&Ff) to 1 revolute-leaved plant (aftffl. 



The cross f . typica M (heterozygous) X f . typica E (a'fiFf X a$f) gave 

 in the FI generation (see table 23) flat-leaved plants (a0Ff) and revolute- 

 leaved plants (a'pff) in about equal numbers, and in the F 2 generation 

 from flat-leaved plants (see table 24) a segregation of 3 flat-leaved plants 

 (a'pFF and a'pFf) to 1 revolute-leaved plant (a'fff). 



The reciprocal cross is missing from the series. 



The cross f. typica M (homozygous) X f. typica C (a'&FF X a@FF) 

 gave in both the FI and F 2 generations (see tables 25 and 26) only flat- 

 leaved plants (a'pFF in both generations) . 



The reciprocal cross is missing from the series. 



The cross f. typica M (heterozygous) X f. typica C (a'QFf X aQFF) 

 gave in the FI generation (see table 27) only flat-leaved plants (afiFF 

 and a'pFf) and in the F 2 generation (see table 28) 11 progenies consisting 

 entirely of flat-leaved plants (a'pFF) and 7 progenies showing a segrega- 

 tion of 3 flat-leaved plants (a'pFF and a'pFf) to 1 revolute-leaved plant 

 (a* ftff) . The ratio 11:7 does not approach as closely as would be expected 

 the ratio of one dominant factor to one recessive factor in the gametes of 

 the heterozygous pistillate parent of the cross. In this table there seems 

 to be a shortage both of segregating progenies and of revolute-leaved plants 

 in the segregating progenies, indicating that the pistillate parent and its 

 progeny produce either fewer or weaker gametes bearing the recessive 

 factor. 



The reciprocal cross is missing from the series. 



A summary of tables 5 to 28, inclusive, is given as table 29. 



VARIOUS PEDIGREES OF PLANTS USED IN CROSSES 



A record of the parentage of all of the plants used in this work is given 

 as table 1. All plants not otherwise designated were f. typica. 



It may be noticed that, though different strains of Oenothera pratincola 

 behave differently as to the mutations that they throw when self -pollinated, 

 and in the way that they behave in crosses, all f. typica plants within a 

 strain, no matter how complicated, by crossing or mutation, their pedi- 



GENETICS 6 : Ja 1921 



