226 



KELLOGG AND BELL 



The mean length is 42.1, the mode 41, the standard devia- 

 tion 2.027, and the coefficient of variation 4.81. This variation 

 is about as extensive as that of measurement b-d, and nearly 

 twice as large as that of the wing's breadth. 



The frequency polygon showing graphically the variation in 

 the vein part^-^ (see fig. n) may be seen in fig. 15. 



The mean length is 21.9, the mode 21 (with 22 almost as fre- 

 quent and 23 only one-fifth less frequent), the standard deviation 

 i .61, and the coefficient of variation 7.3. Thus the variation 

 in the length of this definitely subtended bit of vein is three 

 times as great as the variation in breadth (a direct factor of 

 size) of the wing and one-half larger than the variation in cer- 

 tain other vein parts. 



The same dimensions of the right fore wings namely, breadth, 

 and parts of veins, b-d^f-g and g-h, were measured in a lot of 

 300 workers taken from the laboratory hive (Italians), the same 

 lot in which the variations in the character of the venation of 

 the wings was studied with the results given on p. 217. In addi- 

 tion the lengths of 98 of these wings could be measured (no 



FIG. 16. Frequency polygon of the variation in length of the right fore 

 wings of 98 worker honey-bees taken from laboratory hive ; mean length 214.3 ; 

 index of variability 2.37 ; coefficient of variation i.i. 



lengths could be got in the case of the drones because of the 

 breaking of the wing tips in the drone catcher) and thus a more 

 certain criterion of the extent of variation in size (indicated for 

 the drones by the breadth) obtained. 



