1912] SHULL— LYCHNIS AND PAP AVER 123 



the widely distributed plant-pigment anthocyanin, whose method 

 of origin appears to be in essential agreement with that of melanin. 

 More recently Gortner (6) has shown that anti-enzymes are not 

 necessary for the inhibition in question, as the oxidizing action of 

 tyrosinase is prevented by the presence of small quantities of such 

 relatively simple w-dihydroxyl phenolic compounds as orcin, 

 resorcin, and phloroglucin. Gortner shows that on the basis of 

 his investigations a satisfactory explanation can be given of those 



dominant 



described below. 



exemplified by the Shirley poppies 



I have been making numerous crosses among strains of Lychnis 

 dwica L., and during the past six years have grown about 660 

 pedigreed families of this species. Nearly 300 of these families 

 have resulted from matings between white-flowered individuals, 

 many of the matings having been arranged for the specific purpose 

 of finding different kinds of whites possessing complementary 

 color-factors. Until the past summer (191 1) all of these crosses 

 between white-flowered parents have given uniformly white- 

 flowered progenies, 3 and a similar number of crosses between white 

 and colored individuals have invariably shown the whites to be 

 recessive to colors, though they differed genotypically in that some 

 of the whites carried a factor for reddish-purple and others a factor 

 for bluish-purple, the red being epistatic to blue. 



With the bringing in of two new strains of Lychnis dioica 

 from their native habitats in Germany (for seeds of which I am 

 indebted to Dr. Baur), I have realized the complementary factors 

 for color for which I had been looking thus far in vain. 4 



3 The several purple-flowered individuals from white-flowered parents, mentioned 

 in an earlier paper (Shull 13), appear now to have been plus-fluctuants of a "tinged 

 white' ' which had not been recognized as such at the time that paper was written. 

 They have no bearing on the problem of complementary color-factors here under 

 consideration. 



4 That the several kinds of recessive whites exist among my Cold Spring Harbor 

 strains, though I have not yet made a mating among them between two whites which 

 resulted in a purple-flowered F X| is sufficiently demonstrated by the facts presented 



n my earlier paper. My failure thus far to secure a purple-flowered F t from two 

 whites among these strains must be due to the mere chance that I have not selected 

 whites from the proper families. 



