382 



DWIGHT E. MINNICH 



to the causes noted above, I have included m the polygon only 

 the first four values for each bee, thus giving equal weight to 

 every animal. Of the total two hundred and seven" values rep- 

 resented in the polygon, 81.16 per cent are positive, whereas- 

 only 18.84 per cent are negative, a ratio of over 4 to 1. 



18.84% 



42 



E3 n 



,81.16% 



26 26 



TTT 



-16— 14 —12 -10 -8 -6 -4 -2 2 4 6 8 10 12 14 16 18 20 22 24 2S 



Degrees per cm. 



Fig. 11 Frequency polygon x)f the first four d values of fifty-two bees. The 

 negative values are represented by the shaded areas ; the positive values, by the 

 clear areas. 



' In the case of one bee it was possible to include only three values for d, 

 because of a missing record. See Table 2. (Appendix), bee no. 45. 



