200. BOTANICAL GAZETTE [OCTOBER 
the preliminary name of O. biennis Chicago.3 I shall deal with this 
one under the name O. saligna, and designate the new inconstant 
mutants of O. Lamarckiana as O. cana, O. pallescens, O. Lactuca, 
and O. liqguida. As far as investigated, they all follow the rule 
that in every generation they split up into two ordinarily almost 
equal groups of typical specimens and of atavistic individuals 
which, in all cases, exactly duplicate the characters of O. Lamarck- 
tana. Moreover, they show a relatively high degree of mutability. 
With one of them, O. cana, I have made a number of crosses with 
allied forms, in order to ascertain that it behaves in the same manner 
as O. scintillans, and that the same conception of heterogamy must 
be applied here also. In this mutant the pollen carries only the 
hereditary qualities of O. Lamarckiana, and the specific marks of 
the mutant are handed down to their progeny through the ovules 
only.s This conception of heterogamy may be considered to hold 
good for the other inconstant types also. 
The same behavior is found in O. lata, but since this form never 
produces any fertile pollen in my cultures and has to be fertilized 
by O. Lamarckiana in order to produce seeds, the evidence which 
it affords is less stringent than that given by the self-fertile dimor- 
phic races. 
Ocnothera Lamarckiana mut. cana—Among a number of 
dubious mutants from O. lata which were cultivated as biennials 
in 1906-1907, a plant was noticed in the third generation of that 
family with narrower leaves of a gray color, evidently constituting 
anew type. It was very vigorous, reached a height of about 2 m., 
and was self-fertilized. It will be designated as O. cana from 
lata no. 1, since the first family of O. cana was derived from it. 
Next year the same mutant type was recognized among the 
young rosettes, issuing from different samples of seeds of O. lata 
fig. 1). All in all there were 5 specimens of O. cana. In order to 
determine the frequency of this mutant I have made two cultures 
3 Gruppenweise Artbildung, p. 52. fig. 18 and pl. 6. 1913. 
4In the wild condition such a splitting would evidently cause a race to die out 
after a few generations, especially since the atavists are very fertile and much stronget 
than the mutant form. As a matter of fact, inconstant wild species of this type 
are not known. See The mutation theory, Vol. I, p. 380. 
5’ Gruppenweise Artbildung, p. 273. 1913. 
