CONTENTS 
Page. 
Introduction. 463 
Sex ratio in pigeons. 465 
Is THERE A DIFFERENTIAL MORTALITY?. 466 
The RATIO OF BISEXUAL to unisexual broods and the relation of sex 
TO THE ORDER OF LAYING OF THE EGGS. 478 
Time of laying of eggs a and b . 488 
Time of hatching of eggs a and b . 494 
“Control of sex” in pigeons. 500 
Length of time pigeons will incubate when eggs do not hatch . 502 
Summary. 507 
List of references. 510 
