i8 



BOTANICAL GAZETTE 



[JANUARY 



I crossed them in 1915 and had in 1916 a culture of 60 plants, among 

 which 3 per cent were lucida and 97 per cent brittle rubrinervis. 

 Other types failed, as was to be expected. The seeds of the two 

 lucida plants contained 89 and 95 per cent of good germs. 



Summing up the results of the crosses between O. rubrinervis 

 and O. nanella, we see that they yield exactly the same hybrid types 

 as those with O. Lamarckiana and in corresponding percentages. 



Crosses of O. rubrinervis with heterogamic mutants.— 

 Crosses with the pollen of these forms must simply confirm those 

 with O. Lamarckiana, since their pollen carries mainly the same 

 hereditary qualities as that of the parent species. I fertilized in 

 1913 two plants of my main race of O. rubrinervis with O. cana, two 

 with the pollen of the Lamarckiana-like offspring of self-fertilized 

 scintillans, and added the reciprocal cross of the latter combination. 

 In the following table I shall call these offspring scintillans- 

 Lamarckiana. 



Crosses of 0. rubrinervis with heterogamic mutants 



Cross 



O. rubrinervis X cana 



O. rubrinervis X cana ._ . 



O. rubrinervis X scintillans-Lamarcki- 



ana • • 



O. rubrinervis Xscintillans-Lamarcki- 



ana 



O. scintillans-Lamarckiana X rubriner- 

 vis 



O. scintillans-Lamarckiana X rubriner- 

 vis 



Number of 

 specimens 



60 



57 



60 

 60 

 84 

 34 



Percentage of 



Lamarckiana 



32 

 53 



13 



7 



7 



IS 



lucida 



38 

 32 



3 

 10 



4 

 9 



subrobusta 



30 

 15 



84 



83 



89 



76 



About one-half of each group flowered in August. No brittle 

 specimens occurred. The types were exactly the same as those 

 derived from the cross between O. rubrinervis and O. Lamarckiana. 



If the heterogamic types are used as female parents, the splitting 

 of course will be more complicated. I fertilized a strong biennial 

 specimen of O. scintillans with the pollen of a plant of O. rubrinervis 

 and had in 191 6 a culture of only 23 plants, all of which flowered 

 in August. There were 5 types: 11 Lamarckiana, 2 lucida, i sub- 



