No. 642] VARIATION IN DATURA 



21 



and half should not. Differential mortality, affecting 

 adversely zygotes with the extra chromosome, prevents 

 the expected e<iuality of (2))) and ('2n \- 1 ) individuals in 

 the offspring from test cross. "s with diploids. 



The 12 mutants under discussion mav best be repre- 

 btnted 111 a simple liuuie 1)\ tlieii capsuh's In Figure 4 

 we hn\'e (•a]>sul('S ol the li* smi})hM risomu' mutants viewed 

 iiom h, nx It. M.l. . 11. uln.h i.i)iesents the 



addition ol i Miul. . \'. 1 . ii..iiM..Mi,i, .umablN m a 

 did. K 111 ^. t I li. t. 1^ tn. <doh w nil di DM d c.ipMiles 



