zgig] 



DeVRIES—OENOTHERA rubrinervis 



19 



rohusta, 9 scintillans, and 8 oblonga. The first three were the same 

 as in previous crosses and confirm their result; the last two named 

 t>'pes are the same as are always seen in the first generation of 

 crosses of O. scintillans when this is used as the seed parent. 



Moreover, in 191 5 I fertilized 4 plants of my race of O. lata with 

 0. rubrinervis, counted the lata and alhida in their progeny in May 

 191 6, and for want of space planted out only a part of the others, 

 in order to distinguish the types, but without trying to determine 

 percentage figures. Altogether I had 434 seedhngs, among which 

 7 per cent were lata and 6 per cent albida. At the time of flowering 



I counted 23 Lamarckiana, i lucida, 20 brittle rubrinervis , besides 



II mutants (5 oblonga, 5 obovata, and i scintillans). No subrobusta 

 occurred in these cultures. These results confirm those previously 

 given. 



Second and later generations. — Brittleness and dwarfish 

 stature are recessive characters, and as such may be expected to be 

 split off in the succeeding generations. For the crosses between 

 O. rubrinervis and O. nanella this splitting has already been dealt 

 with. For the other crosses our analytical formula for O. Lamarck- 

 ianaXrubrinervis shows that the types lucida and subrobusta may 

 be expected to produce a splitting, whereas the Lamarckiana-like 

 hybrids cannot contain the necessary factors. The production of 

 brittle plants from subrobusta had been observed in the case of the 

 dwarfs, and so I studied in 1916 the progeny of three specimens of 

 lucida from previous crosses. 



Splitting progeny of O. hybr. lucida; cultures of 19 16 



Moreover, in 19 16 I self -fertilized some specimens of lucida taken 

 in the first generations of the crosses mentioned, sowed their seeds 

 in 191 7, cultivated all the seedlings until the time of ripening their 

 first fruits, and counted them repeatedly during the summer. The 



