New Species of Oenothera 543 



partly this type and partly that of any other of 

 the new species derived from lamarckiana, that 

 might have been used as the pollen-parent. This 

 average seems to be a general rule, recurring 

 in all experiments, and remaining unchanged 

 through a long series of successive generations. 

 The fluctuations around this mean go up to near- 

 ly 50# and down nearly to 1#, but, as in other 

 cases, such extreme deviations from the aver- 

 age are met with only exceptionally. 



The second category includes the inconstant 

 but perfectly fertile species. I have already 

 given the names of the only two forms, which 

 deserve to be mentioned here. 



One of them is called scintillans or the shiny 

 evening-primrose, because its leaves are of a 

 deep green color with smooth surfaces, glistening 

 in the sunshine. On the young rosettes these 

 leaves are somewhat broader, and afterwards 

 somewhat narrower than those of 0. lamarck- 

 iana at the corresponding ages. The plants 

 themselves always remain small, never reaching 

 the stature of the ancestral type. They are 

 likewise much less branched. They can easily 

 be cultivated in annual generations, but then 

 do not become as fully developed and as fertile 

 as when flowering in the second year. The 

 flowers have the same structure as those of the 

 lamarckiana, but are of a smaller size. 



