372 Gates, Studies on the Variability and Heritability of Pigmentation etc. 
WHELDALE, Miss M. (1909): On the nature of anthocyanin. — Proc. Cambridge Phil. 
Soc., 15 pp. 137—168. 
— (1910): Plant oxidases and the chemical inter-relationships of color-varieties. — 
Progressus Rei Botanicae, 3 pp. 457—474. 
Explanation of Plate VI. 
Plate VI. Reproduction of colored paintings of buds of Oenothera vubyinervis, 
natural size, to show the range of color variations. These were used as the types of 
classes in cataloguing the buds examined. They are accurate representations of 
particular individual buds. The individual differences are described in the text. 
Fig. 8 is a bud of O. rubricalyx, having red instead of green hypanthium and red 
median longitudinal ridges. 
Referate. 
Emerson, R. A. Factors for Mottling in Beans. American Breeders’ 
Association 5 1909, pp. 368—376. 
— Inheritance of color in the seeds of the common bean, Phaseo/us vulgaris. 
Twenty-second annual Report, Nebraska Agricultural Experiment Station 
1909, pp. 67—I0T. 
The author summarizes the results of studies by Tschermak, Shull, 
and Emerson on the inheritance of color-characters in beans, with special 
reference to mottling (Marmorierung), and discusses two hypotheses pro- 
posed respectively by Shull and Spillman to account for the facts presented. 
The facts to be accounted for are briefly as follows: 
There are two types of mottled beans, in one of which the mottling 
exists as a normal Mendelian unit-character epistatic to its absence, and 
which may be latent by separation in white races. The latency of this 
type of mottling has been definitely demonstrated by Emerson in the case 
of two varieties of white beans, “Davis Wax’ and ‘White Marrow Field”. 
This type of mottling may characterize pure races, as exemplified by the 
many common varieties of mottled beans. The other type of mottling 
does not appear in any pure race, but is produced as a novelty (Kreuzungs- 
novum) by crossing certain self-colored races with certain other self-colored 
races or with certain white races. In this case mottling appears in all Fı 
individuals, but in the F,, mottled and self-colored individuals are always 
present in approximately equal numbers, giving rise to ratios 1:1 and 
3: 3:2, instead of 3:1 and 9:3:4. In F, and subsequent generations 
these ratios I: 1 and 3:3: 2 are repeated in the progenies of every mottled 
bean, none of them producing only mottled offspring. 
Tschermak explained the mottled beans of this second type as new 
“eversporting half-races’” produced by mutation as a result of hybridization 
(Hybrid-mutation). Shull referred them to a definite gene for mottling 
which he assumed to be capable of manifesting itself only when in the 
