1*0. 550] 



GAMETIC COUPLING 



581 



nificance of crosses of this nature was not realized at 

 the time pollinations were being made, and but 5 ears of 

 this kind were secured. In two of these ears there is a 

 significant correlation. The classes exhibited in the live 

 ears are shown in Table III. 



these ears is as follows : In 1908 a plant of a white Mex- 

 ican variety was pollinated by a Hopi variety with col- 

 ored aleurone, producing a pure white ear, Mhl9. In 

 1909 a plant from Mhl9 was pollinated by white Chinese, 

 the variety possessing the waxy endosperm. The result- 

 ing ear Z)/il4 had white and colored seed in the proportion 

 of 2 white to 1 colored, with no trace of the waxy endo- 

 sperm. In 1910 a plant from a colored seed of DhU was 

 self-pollinated, producing an ear DM42L2 with the fol- 



lowing classes: white-waxy 99, white-horny 89, colored 

 waxv 51, colored horny 348. This represents an associa- 

 tion between colored and horny of .767, almost exactly 

 that expected on a coupling ratio of 3:1, but it will be 



