252 



THE UNFERTILISED EGG AS A 



[PT. Ill 



Fig. 14, taken from Riddle, gives the differences diagrammatically. 

 A glance at it shows that the male-producing egg of the spring 

 contains less stored material than the female-producing egg of the 



Sex conbrol and known correlations in pigeons 



SPRING 



AUTUMN 



d cf cT d* cT ^ $ ^^ *? *$ ^9 •.>' ^ •-': "■ 



9 10 11 12 13 14 



N? 1 



N° <2 



N° 3 



N9 4 



N? 5 



N° 6 



N? 7 



N9 8 



N° 9 



N?10 



.siji 



N0I. shows comparabive size of eggs of Alba (A) 

 and Orienbalis (0) 



Fig. 14. 



autumn. The amount of water and ash present, on the other hand, 

 diminishes, and the rise indeed is mainly to be seen in the fat and 

 lipoid fractions and in the calorific value. Table 7 gives the figures 

 for one individual pigeon during 191 2. The differences are not 



