450 BOTANICAL GAZETTE [DECEMBER 
that it gives no reversions to f. typica. All of the aberrant plants 
in the cultures, both from self-pollination and from pollination with 
f. typica, are mutations belonging to the characteristic group. 
As in the case of mut. formosa, most of the secondary mutations 
were mut. sefacea. 
The small culture of f. typicaX mut. albicans emphasizes the fact 
that the composition of the culture is conditioned by the female 
gamete. As in the case of the 
analogous cross f. ¢ypicaX mut. 
formosa, the progeny is just 
what we should expect from 
self-pollination of the typica 
parent. 
Mut. revoluta—Only one 
small progeny was obtained 
from .this nearly sterile muta- 
tion. It showed that the form 
reproduces itself except for 
throwing other mutations of 
the characteristic group. None 
of the crosses made with mut. 
revoluta were successful, but 
there can be little doubt, from 
collateral evidence, that mut. 
revoluta, as well as mut. albi- 
cans, follows the same type of 
inheritance as mut. formosa. 
Fic. 12.—Mut. formosa: 2 rosettes, Mut. setacea—So far as 
Lexington E-5-206 and 207, from the F: can be determined, this form 
Reig of f. typica; both are shown in comes entirely true from seed, 
a and represents the most 
extreme modification which can take place in the direction 
followed by the group of characteristic mutations. Although 
the crosses with f. typica have so far not been successful, 
it is probable that this extreme reduction phase would also 
be dominant when introduced into the cross as the female 
gamete. 
