1918] DEVRIES—MASS MUTATIONS 409 
gous splittings, and the experiments just described simply confirm 
the conclusions drawn from them (5, pp. 252, 254, 255). 
E. SECOND GENERATION OF CROSSES WITH 0. LAMARCKIANA 
As is well known, the twin hybrids from crosses of O. Lamarcki- 
ana are constant in their progeny, with the exception of the /aeta 
from the crosses with O. Hookeri, which splits into Jaeta and velutina 
in the succeeding generations. For this reason I wanted to know 
whether the triple hybrids just described would be constant after 
self-fertilization or split. I found that none of them split off one 
of the two others, and in so far they were constant. On the other 
hand, some secondary marks, which were not observed in the first 
generation, turned up in the second, and thus the constancy was 
not absolute. Since these splittings had no significance for the 
main object of my study, I have not followed them up. 
TABLE VII 
CULTURES OF SECOND GENERATION 
| Second : 
Cross Cross generation ovata lutea brunnea | contraria 
O. grandiflora Lamarcki- 
Re ee 1914 | 1916 + ~ 
0. oc ovine lorea X La- 
Reg Eat ty lige 1914 1916 + - + ~~ 
oO. : s Remmatekiaesceramet 
Oe 1913 1916 + gs - - 
0, ener tay paar Seatiah 
Sere With occ orcs; 1914 1916 + +. + 78 
O. randitiors Yesalie 1913 1915 + + + = 
O. grandiflora Xnanella....| 1913 1916 + + “t- ti 
grandiflora seaaeareye : 
Pappa aid Gee! 1QI4 1916 + ig - ay 
oO. ara grandiflora. . 1913 1915 ~~ sur a ne 
O. lata X grandiflora..... 1914 1916 + “~ ~ 8 
O. grandiiora ochracea X 
WOkians. 020 1914 1916 + “+ 
O. “grandiflora ochracea X 
NONE 1914 1916 + aE oe 
In respect to the third generation, it was to be expected that it 
would simply confirm the results of the second, and so I have limited 
myself to one culture for each of the three main types and to some 
few for the secondary combinations. Table VII gives a list of my 
cultures of the second generation. They embraced with some few 
