464 



WALTER W. MARSHALL AND HERMANN J. MULLER 



TABLE 1 



grades may be proved to have the order in the series which has 

 been assigned to it. Exception must be made in the case of 

 the last grade, 'large blister,' but in this case the numbers are 

 not large enough to be significant, audit seems fairly obvious 

 that the 'large blister' represents a greater deviation from normal 

 than medium blister (especially since medium blister is shown 

 by the table to be less normal than small blister). 



In table 2 the results for both right and left wings have been 

 added together, but the counts for the stock and outcrossed 

 types are shown separatelj^ 



All counts produced by bottles that were started on a certain 

 date (with similar food) are grouped together, with their results 

 for each day shown on a separate line. It should be stated here 

 that the offspring were kept one day after being taken from the 

 bottle, in order to have both types of approximately the same 

 age when graded. 



it will be seen from these figures that the outcrossed type 

 which has been kept in a state of continued heterozygosis deviates 

 even further from normal than does the stock. The average grade 

 of the former is 4.2, which places this type in 'marked,' and 

 the average grade of the stock is 3.0, or 'moderate.' 



The figures show that in twenty-five cases the stock is weaker 

 than the outcrossed type. In only five cases is the outcrossed 

 weaker than the stock, and in one case both are of the same value. 



