no 



CHARLES ZELENY. 



unit, the result obtained is shown in Table II. and graphically in 

 Fig. 3. In the latter the scale at the left represents the logarithms 



ommatidial 

 means 



120 



110 



100 



90 



80 



70 



60 



50 



40 



30 



20 



10 



temperatures 15< 



ommatidial 

 differences 



60.6 



20° 



39.5 



27< 



19.2 



30< 



21.3 



Fig. 2. The length of each heavy vertical line represents the difference in 

 ommatidial number between homozygous and heterozygous ultra-bar at the 

 respective temperature. The numerical values are given at the bottom of 

 the figure. The heterozygotes have one full and one ultra-bar factor. The 

 scale at the left represents ommatidial numbers. The marked change in the 

 ommatidial difference with change, in temperature is to be noted. 



Table II, 



Factorial Values. 



Eight Per Cent Units. 



IS 



One full eye and one ultra-bar factor. 



Heterozygote 



Two ultra-bar factors. Homozygous 



ultra-bar 



Difference in eight per cent, units or 



temperature units 



+25.3 



+15-3 

 10.3 



+ 19-6 



+ 9-4 



10,2 



+ 12.3 

 + 3-9. 



+ 11. o 



0.0 



11.0 



