334 



riddle: control of sex ratio 



male-producing egg of the spring is an egg that stores less ma- 

 terial than does the female-producing egg of the autumn. (2) 



TABLE 8 



Stored Energy of Eggs (1914) of Streptopelia risoria ( $ 558) as Determined 



by the Bomb Calorimeter 



"This egg was not only the first laid during season, but first during life of 

 this bird. 



6 The percentage differences are based upon a value of 100 per cent for the 

 smaller egg of the pair. 



That the male-producing egg of the clutch stores less material 

 than does its female-producing mate. (3) That the eggs of old 



