EFFECT OF SEASON OF HATCHING UPON DLSTHIBUTION OF FERTILITY. 



63 



It is elsewhere shown that the germs of pigeons produced late in the season, 

 particularly when the parents have been made to overwork at reproduction, have 

 lower developmental power than have the earlier produced gametes from the same 

 parents. ^ It is also elsewhere shown that the sex-ratio and the longevit}^ of the 

 young produced from such eggs with lowered developmental strength are modified— 

 more females and a shorter life-term result from such gametes. In this chapter 

 is presented the issue of a thoroughgoing comparative test, made upon a large 

 family of Japanese turtle-doves, which had as its purpose the definition of the limits 

 of fertility of each of the several members of the family, and thus to learn whether 

 those individuals which were themselves developed from germs of different levels 

 of developmental power, according to season, do or do not in their turn show, deliver, 

 or transmit their own particular level of developmental strength or fertility to 

 their own germs. 



' Where brackets are placed, the ordei 

 - That is, eggs by the female of the pni 



thin the clutch 



