Dec, 1915-] 



Harris : The Beetle Bruchus, 



247 



ages from the average condition is so great that they must unquestion- 

 ably be regarded as statistically trustworihy. Only in the case of the 

 lowest ovule class of the Golden Wax series is there an exception to 



Diagram 2. Relationship between number of ovules per pod and para- 

 sitization by Bruchus in Burpee's Stringless beans. See Explanation of 

 Diagram i. 



the rule of an increase in percentage of parasitization from lower to 

 higher ovule grades. The graph shows by the enormous extent of 

 the shaded area at the point of two ovules per pod that the probable 



Diagram 3. Relationship between number of seeds matured per pod and 

 parasitization by Bruchus in Golden Wax beans. 



