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THE AMERICAN NATUBALIST [Vol. LIII 



the factors of chlorophyll color G, with another aleurone 

 color factor, this time the R factor, which in the presence 

 of a suitable basic factorial combination produces red 

 color in the aleurone cells. More recently Lindstrom 

 (1918) has found another chlorophyll factor L linked with 

 R and G. L is completely linked with R and both show 

 al)out the same amount of breaks in the linkage with G. 

 This makes the first group of three factors so far reported 



LtXKAGE BFiTWEEX TUXICATE EaR AXD StARCHY-SwEET 



Endosperm Factors 



The curious type of maize, known generally in this 

 country as pod corn {Zea mays tunicata Sturtevant) is 

 considered by Collins (1917) not to be a pure type, but a 

 heterozygous condition somewhat analogous to t*he blue 

 Andalusian fowl. Wlien selfed seed of the ty-pical podded 

 ears are planted Collins finds that three types of plants 

 are produced: one type like the typical podded parent; 

 one with normal ears without the enclosing glumes; and 

 one anomalous type of a plant which does not produce 

 seed in lateral inflorescences, but in perfect flowers in the 

 tassels. On these last plants lateral inflorescences with 

 much elongated glumes are produced, but are sterile. All 

 these three types have been secured in about the ratio of 

 1:2:1 as expected on the assumption that a single Men- 

 delizing difference is involved and the heterozygote is 

 distinguishable from both homozygotes. 



Our own rather limited experience with this type of 

 maize confirms Collins 's conclusions. In 1915 seed of a 

 typical podded ear was planted (there was no record 

 whether it had been selfed or not). All three types which 

 Collins described later were obtained. A number of t>i>i- 

 cal podded plants were self-pollinated and grown the 

 next year in the hope of getting a pure podded strain. At 

 that time no thought was given to the possibility of its 

 lu'inu- a h('t«'fozyoT)ii^ type. The plants with seeds in the 

 tM-M'l- wt'iv tlu night to he extreme variations from the 



