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THE AMERICAN NATURALIST 



[Vol. L 



inadequate and useless one for a study of the problem. 

 It is now clear that the method that would be valuable for 

 this purpose must be a thoroughly analytical one. Whit- 

 man has properly analyzed this situation. He has shown 

 that normally— ■%. e., with effects of crossing eliminated— 

 from the periods for the production of the strongest 

 germs an undue proportion of pairs of eggs produce 

 males; and from the opposite period there arise undue 



