INHERITANCE OF ENDOSPERM COLOR IN MAIZE^ 
Orland E. White 
Few of the many characters in plants and animals studied by 
geneticists during the last seventeen years are now to be regarded as 
inherited in simple fashion. As more detailed and extensive studies 
on the heredity of each type of character, once regarded as a simple 
unit, are made, the more various the facts and the more complex the 
interpretations have become. The present paper describes such an 
increase in complexity of fact and interpretation in the heredity of 
endosperm color in maize, which at the outset was regarded as a 
single allelomorphic pair consisting of yellow and white, but which at 
present involves possibly as many as four pairs of factors, one of 
which brings about a dominance of white. 
As studied and interpreted by Correns (3, 4) and Lock (10) and 
others, yellow endosperm in maize is determined by the presence of a 
factor for yellow, in the absence of which, the endosperm remains 
white. Lock (10) found various degrees of yellow among the grains 
classified as yellow, but all were easily separated from the white, so 
that he regarded them as fluctuations of slight importance, and, in his 
interpretation, did not distinguish between them. He notes, however, 
that on the average, homozygote yellows are deeper colored than 
heterozygotes. Lock studied very large numbers of F2, F3, and F4 
generation hybrid plants from crosses of yellow and white endosperm 
varieties. Back-crosses of the yellow heterozygote with the recessive 
white homozygote were also made in large numbers. The numerical 
results are very slightly vitiated by the technique used, but the 
numbers are so large as to make the small error from this source, in 
this particular case, of comparatively slight importance. Lock's 
results are summarized in Table i . 
Further studies by East and Hayes (5, 7), Burtt-Davy (i) and 
others on these endosperm colors brought to light a more complex 
state of affairs, for they found two yellow endosperm "colors" in 
maize, each behaving, when crossed with non-yellow (white) endo- 
1 Brooklyn Botanic Garden Contributions No. 18. 
396 
