464 COBB AND BARTLBTT: INHERITANCE IN OENOTHERA 



a 



characteristic being mut. nummularia. There is also one highly 

 mutable (mass-mutant) strain, Lexington B, which gives rise in 

 large numbers to several kinds of revolute-leaved mutations, 

 produced by no other strain. The most notable of them is mut. 

 formosa. Lexington E also throws some of the flat-leaved muta- 

 tions which are more commonly met with in the other strains, 

 but mut. nummularia has never appeared among them. 



All experiments thus far made with the revolute-leaved muta- 

 tions indicate that in crosses with f. typica of the same strain in- 

 heritance is matroclinic. Their behavior affords a parallel to 

 that of Oenothera Reynoldsii and its mutations.^ Because of 

 their markedly dissimilar mutation phenomena, it was suspected 

 that the rule of matroclinic inheritance might not hold in crosses 

 between strains C and E. In order to test this point, and also 

 to determine the effect of crossing on the mutability of the 

 strains, the following pollinations were made in 1915: 



f. typica C X f. typica E (unsuccessful). 



f. typical E X f. typica C (unsuccessful). 



f. typica C X mut. formosa E (successful). 



mut. formosa E X f. typica C (unsuccessful). 



mut. latifolia C X nmt. foj-mosa E (unsuccessful). 



mut. formosa E X mut. latifolia C (successful). 



mut. gynocrates C X rrmt. formosa E (successful). 



mut. formosa E X mut. gynocrates C (successful). 



Unfortunately, as indicated above, several of the more im- 

 portant crosses were unsuccessfully attempted. An effort to 

 repeat them in 1916 failed because of unfavorable weather con- 

 ditions. No significance is attached to* the failures, since it is 

 believed that all of the forms are fertile inter se. Probably the 

 next repetition of the crosses, under favorable conditions, will re- 

 sult in a complete series. In any event the delay in rounding out 

 the experiment must be considerable, and since important re- 

 sults have aheady been obtained we have determined to present 

 the data at hand. 



^ La Rue, Cari, D., and BartlETT, H. H. Matroclinic inheritance in mutation 

 crosses of Oenothera Reynoldsii. Amer. Joum. Bot. 4: 119-144. 1917. 



