COMPARATIVE VARIABILITY IN THE HONEY BEE. 21 



about the same degrees of variability of the two sexes. Any 

 other veins or cells would no doubt show like variations. 



Length of Vein R. In the typical hymenopterous wing the 

 media (M) branches from the vein R + J/ at a 1 point nearer the 

 base of the wing than in Apis. The length of the vein R + M 

 would therefore be desirable for measurement, but from the diffi- 

 culty of getting exact measurements this was discarded, and in its 

 place we took the measurement from the point where M branches 

 off from R + M to the point where R divides into R l and Rs or 

 the length of R, which is therefore shorter than in the typical 

 hymenopterous wing. 



Diagonal Length Cell R 4 . In the typical hymenopterous 

 wing veins R 4 and R 5 are nearly at right angles to the vein from 

 which they branch, while in the bee, R 4 is bent out to about 

 135 and R 5 to 160. This makes the cell R 4 considerably longer, 

 and the diagonal length varies according as the angle R 4 Rs 

 varies. The measurements were made from the proximal side 

 of R 5 Rs to the anterior angle of R 4 J/,. 



Length of Veins M, and in. In the bee's wing there is a bend- 

 ing in of the veins M 4 and M s toward the base of the wing with a 

 corresponding lengthening and shifting of vein m. This vein 

 gives a convenient measurement for the relative length of wing 

 since it varies almost directly as the length increases. J/ 9 was 

 chosen because it is correlated in its length with ;//, and forms a 

 convenient relative measurement for the breadth of the wing. 



Ratio between m and M. r As stated above, the lengths of m 

 and M. y are correlated in their variation, so in order to test the 

 relative variabilities of the two veins in drones and workers, we 

 computed the ratios between the two M z : m \ : i : x ; x in 

 every case being carried to two decimal places. From these 

 computations it was found that the variation of m is in inverse 

 proportion to that of J/ 9 as will be shown later. 



Number of Hooks on Hind Wing. This count was taken to 

 see whether the hind wing varied as did the fore wing, and the 

 number of hooks served as a conservative test. 



Besides these measurements and calculations we looked for 

 cases of abnormal wings in which the subcostal (Sc], radius- 

 two (R. 2 ] and cubital-two (Cu.^) veins might be present, these 



