No. 524] 



NOTES AND LITERATURE 



505 



yellow (xantheic) pigment arises which, when unmodified by 

 ferments, gives rise to flowers with yellow lips, though the throat 

 is ivory white. In some strains this yd low chromogen appears 

 to be modified by a ferment (I) in such maimer as to give flowers 

 having both lips and throat ivory white (except for certain 

 patches of yellow in the palate). An oxidase (L) acting on 

 Y as modified by I gives a tinging of magenta color in the lips. 

 L acting on Y in the absence of I gives crimson. A factor T, 

 when present, causes the magenta color to extend from the lips 

 into the tube. A factor D, probably also a ferment, deepens the 

 shade of magenta, giving the color of the wild plant. D acts 

 only in the presence of Y or I and L and T. Still another 

 factor further intensifies the shade of color. Striping also 

 occurs, the factor for striping being allelomorphic to D and re- 

 cessive to it. There is also a concentration factor S. When 

 S is homozygous the stripes are of an ivory background; when 

 heterozygous the stripes are of a pale-colored background. 

 Chemical studies indicate each of the color factors to be due to 

 different definite compounds. An albino variety arises in the 

 absence of Y. The albino is distinguishable from the ivory white. 



Miss Marryatt, in the same volume, gives the results of the 

 study of color inheritance in MirabUis Jalapo. She finds a fac- 

 tor C for colored sap and a factor M which turns yellow sap red. 

 One white strain was found to be lacking in both ( ' and M. An- 



yellow gave red. The formula of the yellow strain was CCmm. 

 The formula of the crimson strain was CCMM. Yellows hetero- 

 zygote for C were paler in color than the corresponding homo- 

 zygotes. Heterozygotes of the composition CcM M were magenta ; 

 those of the CCMm an orange-red, and CcMm magenta rose. 

 The behavior of "flaking," a form of striping, was not fully 

 made out. 



Miss Wheldale also gives some very interesting results in an- 

 other part of the report on the physiological interpretation of 



which sets oxygen free from X; X is a substance 

 tions as a peroxide ; A is a ferment or oxidizer which 



