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FIG. 24. Frequency polygon of the variation in number of costal hooks of 

 the left hind wings of 299 worker honey bees taken from laboratory hive at one 

 time; mean 21.13; index of variability 1.581 ; coefficient of variation 7.48. 



FIG. 25. Frequency polygon of the variation in number of costal hooks of 

 the right hind wings of 293 worker honey bees taken from laboratory hive at 

 one time; mean 21.4; index of variability 1.462; coefficient of variation 6.8. 



