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



THE SECOND GENERATION. 



THE SECOND BROOD OF EGGS. 



Length of incubation. — Egg deposition of the second brood was 

 found to cover a period of practically one month, extending from 

 June 11 to July 12, and only a slight variation in the length of the 

 several incubation observatious is noted. It may be found by com- 

 parison that this period is practically 14 days shorter than the cor- 

 responding period for the first generation. In Table XLIII are 

 included the records for 505 observations. The length of incuba- 

 tion varied here from 4 to 7 days. An average of 4.9 days is described 

 for the entire period. 





