14 



FAUNA OF MAYFIELD'S CAVE. 



June, 22.9°; July, 25.2°; August, 24.4°; September, 20.4°; October, 

 15.5°; November, 7. 8°; December, 0.5°. 



In fig. 1 are graphs showing the following temperatures: (I) at 

 "42," taken once for each month from September to June; (II) the 

 average temperature at Bloomington for the week preceding the tak- 

 ing of each cave temperature; (III) the average temperature for each 



month from September 

 to June. This figure 

 shows at a glance the 

 relative constancy of 

 the cave temperatures. 

 Perhaps this is still 

 better shown by fig. 2, 

 which represents maxi- 

 mum and minimum 

 temperatures through- 

 out the cave and out 

 side. Graph I repre- 

 sents maximum sum- 

 mer and Graph II 

 minimum winter tem- 

 peratures. 



Consideration of fig. 

 2 discloses another in- 

 teresting thing. Where- 

 as during winter the 

 minimum temperature 

 from "25" to the mouth 

 is much below 11.6° C, 

 which may be consid- 

 ered the normal tem- 

 perature for the cave, 

 during summer the 

 maximum for the same 

 part of the cave is very 

 little above this aver- 

 age. This pecuharity 

 is explained in connection with the discussion of the air-currents within 

 the cave. 



There is little fluctuation in temperature in the side passage at " 26, " 

 where the air-currents are not effective. 



Fio. 2.— Diagram Showing maximum and minimum tempera- 

 tures throughout the cave and at the mouth outside (*). 



