18 



MASS. EXPERIMENT STATION BULLETIN 261 



Figure 2. The Percentage of Eggs Hatching in Controlled Environments. 

 • — Constant Environments; O — Varied Environments. 



30 



40 



50 



60 



70 



80 



90 



37 



32 



?>27 



5 



^22 



17- 



30 



ZONE I 



37 



■32 



:27 



22 



17 



50 60 70 80 90 



RELATIVE HUMIDITV—PER CENT 



Figure 3. The Length of the Incubation Periods in Controlled Environments. 

 • — Constant Environments; O — Varied Environments. 



30 



40 



50 



60 



70 



80 



90 



37- 



32 



I 

 'I 



I 



vt22 



17 



ZONE En 



12 



30 



40 



37 



■32 



17 



50 60 70 80 90 



RELATIVE HUMIDITy-PER CENT 



