STUDIES OF VARIATION IN INSECTS 



229 



The frequency polygon showing the variation in length of 

 the vein part f-g, is as follows : 









FIG. 19. Frequency polygon of the variation in measurement f-g (see fig. 

 n) of right fore wings of 296 honey bee workers taken from laboratory hive at 

 one time ; mean length of this wing part, 31.8 micrometer units ; index of varia- 

 bility, 1.732; coefficient of variation, 5.446. 



The mean length is 31.8, the mode 31, the standard deviation 

 1.73, and the coefficient of variation 5.44. 



The frequency polygon showing the variation in the length 

 of the vein part g-h may be seen in fig. 20. 



The mean length is 18.1, the mode 18, the standard devia- 

 tion .959, and the coefficient of variation 5.3. 



Several other smaller lots of drones and workers from differ- 

 ent hives were examined for this variation in length of vein 

 parts and size of whole wing, the right fore wings being re- 

 moved, mounted and measured under magnification. These 

 lots agree so closely with the conditions just tabulated for the 

 larger lot from the laboratory hive that it will be unnecessary to 

 give space here to the specific data for these several smaller 

 lots. In all these lots the variation in the parts of the veins are 



