168 CLYDE C. HAMILTON. 



CHART I. 



Graph i shows the control of an Evarthrus sodalis larva in still air at a temperature 

 of 20 5 C. 1 



1 Where different temperatures, relative humidities, rates of air flow, and per- 

 centages of gas are given, the one on the left side of the cage is named first, the 

 middle second, and that on the right side last. 



Graph 2 shows the leaction of two Eiaithrus sodalis larvae to dry air at a tem- 

 perature of 21 C. Relative humidity of the air, wet 81 per cent., medium 47 per 

 cent., dry 17 per cent. Rate of air flow 13.3 liters per minute. The larvae had been 

 kept inside at a temperature of 20 to 21 degrees C. 



Graph 3 shows the leaction of an Evarthrus sodalis larva to dry air at a tempera- 

 ture of 17 C. Relative humidity of the air, wet 82 per cent., medium 55 per cent., 

 dry 4 per cent. Rate of air flow 13.3 liters per minute. The larva had been kept 

 inside at a temperature of 20 to 21 C. 



Graph 4 shows the reaction oi an Evarthrus sodalis larva, which had been kept 

 outside in freezing weather for five days, to a high temperature and a low per- 

 centage of moisture. The experiment ran for forty minutes, the second half of the 

 graph starting at "X." Temperatuie of the air, wet 28 C., medium 26.5 C., dry 

 25.5 C. Relative humidity of the air, wet 40 per cent., medium 26 per cent., dry 

 I per cent. Rate of air flow 13.3 liters per irinute. 



Graph 5 shows the reaction of an Evatihrus sodalis larva, which had been kept 

 outside in freezing and thawing weather for 18 days, to dry air and a temperature 

 of 22.5 C. Relative humidity of air, wet 95 per cent., medium 63 per cent., dry 

 4 per cent. Rate of air flew 13.3 liters per minute. 



Graph 6 shows the reaction of an Evarthrus sodalis larva, which had been outside 

 in freezing weather for five days, to dry air and a temperature of 16.5 C. Relative 

 humidity of the air, wet 94 per cent., medium 52 per cent., dry 4 per cent. Rate of 

 air flow 13.3 liters per minute. 



Graph 7 shows the reaction of an Eva/thrus sodalis larva to different rates of air 

 flow. Temperature 18 C. Relative humidity of air, 44 per rent, at the start and 

 39 per cent, at the end. Rates of air flow, o, 13.3, and 69.5 liters per minute. 

 Evaporation from atmometers for 20 minutes, o, .94 c.c. and 2.25 c.c. 



