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LINDSTROM, GENETICAL RESEARCH WITH MAIZE 343 
te purple (showing surprisingly little purple color) type is crossed with 
the sun-red type (with no purple). The F, of this cross consists of full 
purple plants with a great amount of pigment. An indentical F, results 
from a cross of the brown type X the dilute sun-red, neither parent 
showing any purple pigment whatsoever. 
Silk Color. — The inheritance of the anthocyanic pigments in the 
silks of the pistillate inflorescence has been reported by Anderson 
(1921). Colors of the silk are considered while still under the husks since 
parts exposed to sunlight may be red if the necessary factors are pre- 
sent. 
Anderson has formulated and verified the following hypothesis: — 
A Sm P — green silks 
ARS MIDI, à 
A sm P — salmon colored silks 
A sm p — brown 
In the above À is the general factor for anthocyan (used in aleurone 
and plant color studies) and Pp is the general factor pair for pericarp 
color (red or colorless). With aa present in the above series of factors all 
the silks are green. 
Variegation and Mutation 
One of the most interesting and unusual phases of heredity is exhi- 
bited by the behavior of the variegated pericarp condition in maize. 
Here is a legitimate hereditary character whose genetic behavior is 
best explained by a simple process of budmutation with a frequency 
that permits detailed analysis ((Emerson 1914, 1917 and 1922). 
There are distinct commercial varieties of maize (calico or bloody- 
butcher” corn) whose seed-coat is characterized by narrow, longitudi- 
nal stripes of red color on a colorless back ground. The pericarp, being 
maternal tissue, should be uniform on the entire ear, within reasona- 
ble limits. But in these varieties occasional seeds, or blocks of kernels 
of a definite pattern are entirely red. Sometimes an entire ear of an O- 
therwise variegated variety is solid red. Often the second ear of sucha 
plant retains the striped varietal characteristic. | 
When the red kernels of such a variation are planted there is a mar- 
