NATURAL CONTROL IN VARIOUS LOCALITIES. 39 



about 69 per cent. From June 25 till after September 10 showers 

 were of frequent occurrence and the records show during this period 

 an average relative humidity of 75 per cent. Doubtless very signifi- 

 cant facts might be learned if for other localities data similar to those 

 obtained for Calvert were available for comparison. 



INFLUENCE OF CLIMATIC CONDITIONS ESPECIALLY. 



In further determining whether climatic conditions were the most 

 important factors affecting the total mortality percentages, con- 

 clusions may be more readily drawn by arranging the data in three 

 groups, ranging from the highest total mortality to the lowest. 

 Group A may include the eleven localities having a total mortality 

 above the average of 52 per cent, ranging from 84 to 52.5 per cent. 

 Group B may include seven localities having a total mortality ranging 

 from 51.4 to 39.4 per cent. The division between Group B and 

 Group C is made because of the rather large difference in percentage 

 of total mortality shown between 39.4 per cent, the lowest in Group B, 

 and 28 per cent, the highest in Group C. Group C includes ten local- 

 ities with the total mortality percentage ranging from 28 per cent to 

 zero. Each group is summarized to facilitate a general comparison 

 of the average results of the observations made and of the average 

 climatic conditions prevailing. The data are presented in Table VII. 



