280 PROCEEDINGS OF THE ACADEMY OF [June, 



family flying in Bulgaria, with a few exceptions, have greater wing- 

 expansion than those of the same species found in Germany or in 

 France. He attributes this to the difference of temperature. 

 We have several other instances concerning the size of the 

 butterflies of this subfamily diminishing gradually under compara- 

 tively high latitudes. All these instances are not in accordance 

 with my result. In g-i once more we meet with such an instance of 

 the differences in the wing-length as is opposed to the facts hitherto 

 commonly acknowledged and especially to the results of observations 

 made by Bachmetjew. On examining ten Bulgarian species of this 

 subfamily, he has concluded that the wing-expansion of the females 

 more or less exceeds that of the males. The case is quite the 

 reverse with Ypthima philomera var. argus, the males having on an 

 average longer fore wings than the females. It is true that this 

 species shows a sexual difference in the shape of the fore wings, 

 their anterior angles being a little more obtuse in females than in 

 males; but this difference is never so great that it can reverse the 

 situations of the two sexes. I cannot interpret the above-mentioned 

 discrepancies between the present results and those hitherto obtained 

 but to attribute them to the differences between the species. 



The Standard Deviations and the Coefficients of 



Variabilities. 



The standard deviations and the coefficients of variation do not 

 represent anything as distinct as the case of means. They are 

 fairly great, however, in Lot I, differing so much from those of Lot 

 II or III as to claim to be considered probably significant; thus: 



* the difference between Lots I and II 

 0.287 =■= 0.077 



a the difference between Lots I and III 

 0.247 * 0.076. 



C the difference between Lots I and II 

 1.26 * 0.40 



C the difference between Lots I and III 

 0.89 =*= 0.40 



If we call to mind that the individuals included in Lot I are such 

 as had distinctly longer caterpillar stages than in the other lots, 

 this fact may deserve our special notice. 



