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AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
seed, but if it does not there must have been very irregular migration of 
endosperm nuclei after non-disjunction occurred. In material involving 
C c Su su and A a Wx wx, 6 of the 22 seeds showing aberrant aleurone 
color were mottled. Practically all of the normal seeds in material where 
R r IS involved were mottled, and the aberrant seeds showed mottling in 
the colored part (fig. i, A and E), but mottling is known to occur commonly 
in aleurone heterozygous for R when R enters with the sperm and r r with 
the polar nuclei and, whatever its ultimate cause, it is not to be confused 
with what is here termed aberrant endosperm. 
Summary 
It has been shown that, when aberrant seeds occur in crosses in which 
recessive aleurone and endosperm characters are contributed by the female 
parent and the corresponding dominant characters by the male parent, 
spots of the recessive (maternal) aleurone color are in the great majority 
of cases underlaid by the recessive (maternal) type of endosperm if the 
genes for these aleurone and endosperm characters are genetically linked, 
as shown by breeding tests, while similar recessive aleurone-color spots are 
always, so far as observed, underlaid by the dominant (paternal) type of 
endosperm and recessive endosperm parts are overlaid by the dominant 
aleurone color if the aleurone-color and endosperm-composition genes are 
not linked. 
These facts are held to support the hypothesis of occasional aberrant 
chromosome behavior — possibly non-disjunction — and are incompatible 
with the earlier hypotheses involving failure of normal fusion of the second 
sperm nucleus with the polar nuclei, and also make untenable, except in 
rare cases, the hypothesis of somatic mutation. 
LITERATURE CITED 
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52: 57-61. 1918. 
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Plant Ind., Circ. 132: 19-21. 1913. 
Collins, J. L. Chimeras in corn hybrids. Jour, Hered. 10: 3-10. 1919. 
East, E. M. Xenia and the endosperm of angiosperms. Bot. Gaz. 56: 217-224. 1913. 
, and Hayes, H. K. Inheritance in maize. Conn. Agr. Exp. Sta. Bull. 167: 1-141. 
1911. 
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. A fifth pair of factors, A a, for aleurone color in maize, and its relation to the C c 
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Eyster, W. H. The linkage relations between the factors for tunicate ear and starchy- 
sugary endosperm in maize. Genetics 6: 209-240. 1921. 
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12: 76-83. 1921. 
Kempton, J. H. Inheritance of waxy endosperm in maize. U. S. Dept. Agr. Bull. 754: 
1-99. 1919. 
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