68 BULLETIN 429, U. S. DEPARTMENT OF AGRICULTURE. 



THE THIRD GENERATION. 



THIRD BROOD OF EGGS. 



Time of incubation — Eggs of the third brood were found in the 

 field July 10, and deposition continued more or less regularly until 

 August 11, a period of slightly more than one month The length of 

 this period of deposition is found by comparison to be practically iden- 

 tical with that of the second brood, but is exceeded by the correspond- 

 ing period of the first brood by 13 days. Of 180 observations made, an 

 average incubation period of 5.3 days is found. These records appear 

 in Table L. In comparing this period with average incubation 

 periods of the previous broods, it will be noted that the first brood 

 experienced a somewhat longer incubation period, it being 5.96 days, 

 while that of the second brood was somewhat shorter, 4.9 days. 



