1912} The Gloomy Scale 91 



we have never discovered any males, although we have inspected 

 hundreds of trees, most of which were very badly infested, and 

 certainly if males occurred in anyways normal proportions we 

 would have discovered them. At other times we have examined 

 and counted hundreds of scales on selected twigs, and found them 

 all females. Of course parthenogenesis is a possibility, but it 

 does not occur normally in nearly related species ; and that 

 leads us to believe that it does not occur here. Although we 

 are almost forced to believe that fertilization, if it occurs at all, 

 occurs in only one generation out of the several generations 

 each year. 



