ON TRIPLE HYBRIDS. 503 



Summary. 



1. Triple hybrids are produced in crosses of Oenothera scintillans 

 and 0. lata by such species as produce twins from 0. Lamarckiana. 



2. The species investigated are 0. strigosa Rydb., 0. Hooker i T. 

 and G., and one of the American subspecies of 0. biennis. 



3. Of the triple hybrids, two are the same as the twins from the 

 corresponding Lamarckiana crosses and bear the characters of 

 0. laeta and 0. velutina combined with those of the other parent. 



4. The third type resembles the mother (0. lata or 0. scintillans), 

 but in its special marks is also intermediate between its parents. 



5. The laeta and velutina are constant and uniform in their succeed- 

 ing generations, so far as experience goes. In this respect they follow 

 the rule for the twin hybrids of 0. Lamarckiana. 



6. The lata, however, in the only case tried, repeated the splitting 

 after self-fertilization, producing, however, only lata and velutina. 



7. It seems probable that the whole progeny of the crosses named 

 should split up into two equal parts, laeta and velutina, and that each 

 of them should produce a certain percentage of lata. In this way 

 quadruple hybrids would arise. 



Amsterdam. 



f Botanical Gazette 47 : 1-8, January igog.) 



