230 



KELLOGG AND BELL 



approximately twice as large as the variation in the breadth 

 (= size) of the wing, and the variation in drones and workers is 

 (relatively) nearly the same, with the preponderance slightly 



^Classes IS 



Fig. 20. Frequency polygon of the variation in measurement ff-/i (see fig. 

 11) of the right fore wings of 297 worker honey bees taken from laboratory hive 

 at one time; mean width, 18. i micrometer units; index of variability, .959; co- 

 efficient of variation, 5.3. 



with the workers, a condition identical with that in the larger, 

 laboratory-hive lot. 



Variation in Number of Hooks on Costal Afarg-in of Hind 

 Wings. — The two wings of each side are fastened together, 

 when outstretched in flight or in ''ventilating," by a series of 

 small strong recurved spines or hooks along the costal margin 

 of the hind wing (figs, i and 21) which "catch" or "hook 



