

22 



BOTANICAL GAZETTE 



(JANUARY 



having the low figures of O. Lamarckiana. This splitting may be 

 considered, therefore, as amphiclinous, 13 73 per cent of the hybrids 

 belonging to the one and 27 per cent belonging to the other parental 

 type. The splitting is analogous to that of the cross O. Lamarck- 

 ianaXnanella, which gives, under ordinary circumstances, in the 



* 



first generation about 78 per cent tall and 22 per cent dwarfish 

 specimens. It must be pointed out, however, that here the germs, 

 which belong to the next generation, are dealt with as a mark of the 



first generation. In this respect they may be compared with the 

 rudimentary ovules of Geerts, which are not fertilized. 



I tried also the blandina plants of the same crosses, but had 

 fertilized only two specimens of each, which is too few to study 

 this phenomenon. I found 77 and 69 per cent, 67 and 60 per cent, 

 and 71 and 70 per cent of good grains among their seeds. It is 

 remarkable that all of these plants had about the same figure, which 

 is far less than that of the specimens of the pure race of O. blandina 

 (about 95 per cent), but a splitting did not show itself. 



The same difference as between the laeta and extracted velutina 

 was shown by the subrobusta and the velutina from the crosses with 

 O. rubrinervis. I found the figures as given in table V. 



TABLE V 



Cross Hybrid 



Percentage of germs 



0. rubrinervis X blandina 



subrobusta 



m 



blandina 



a 



97 

 96 



70 

 80 



96 

 96 



68 

 75 





0. blandina Xrubrinervis 



96 



0. rubrinervis X blandina 



z? v 



0. blandina Xrubrinervis 



m 







It is possible, however, that this difference is only an effect of 

 the higher exigencies of the plants of the type of blandina y since we 

 have already seen that their amount of good grains is easily dimin- 

 ished by an unfavorable culture. Moreover, this character is not 

 a constant one, for in trying the blandina plants of the second gen- 

 eration I found their contents of normal embryos complete, no 

 single empty grain being found in lots of 200 seeds of two such 

 plants. 



** Uber amphikline Bastarde. Ber Deutsch. Bot. Gesells. 33:461-468. 1915. 



