204 



INHERITANCE, FERTILITY, AND SEX IN PIGEONS. 



The results of two such reciprocal crosses incubated simultaneously, and with 

 the eggs of the crossed birds interchanged with uncrossed birds for incubation 

 purposes, may be found in table 185. It is there indicated that the sperm of the 

 male tumbler added 7 to 24 hours to the incubation period. 



Eggs from a further cross between a male ring-dove and a female homer were 

 incubated simultaneously with eggs from three pairs of common pigeons. The 

 result, as seen in table 186, indicated a shortening of the period by about 8 to 26 

 hours as a result of fertilization by the ring-dove male. 



I have studied the incubation period of the eggs of the wild passenger-pigeon 

 migratorius) and have also obtained data on the length of this period 



TABLE 182 Inn/lint ian time of <? common dove (Z) X 9 ring-dove (D 2). 



Time: May 3, l!S9(i, to Aii(>. 22, 1S97; 41 eggs; raised 4 males; 7 hatched; 10 fertilized. 



