100 Gerald F. Hill: 



the sun, excepting during the morning and late aft^ernoon. One- 

 fly emerged on the sixth day, one on the seventh day, and one on 

 eleventh day. The remaining forty-six pupae were found to be- 

 dead on November 5th. A thermometer exposed to the above 

 conditions registered a maximum of 68°F., and a minimum of 

 44°F., during these eleven days, and a maximum of 86°F., and a 

 minimum of 43°F., for the thirty-five days following the commenc- 

 ing date of this experiment. 



Thus 6% of these pupae remained viable, and produced youngs 

 flies from six to eleven days from date of their removal from the- 

 host. 



Experiment No. 30. 



The above experiment was repeated with fifty pupae collected on 

 October 2r..ci. One young fly emerged on tH:e twenty-second day,, 

 one on th*© twenty-fourth day, and one on thirty-fourth day. On 

 the thirty-fourth day it was found that four pupae were missing 

 (probably taken by birds). The remaining forty-three pupae were' 

 then examined and found to be dead. 



Thus 6% of the pupae remained viable and produced young 

 flies within from twenty-two to thirty-four days of their removal 

 from the host. During the period the maximum temperature was- 

 86°F. and the minimum 34°F. 



Experdment No. 31. 



The preceding experiment was duplicated on the same day. None 

 of the pupae produced young flies, and all were found to be dead 

 thirty-eight days later. 



Experiment No. 32. 



An experiment similar to the three preceding experiments was 

 commenced on November 21st, with thirty-three pupae of unknown- 

 ages. None of these pupae produced young flies during the follow- 

 ing forty days, at the end of which period they were examined and 

 found to be dead. The maximum temperature recorded for the first 

 eighteen days was Si^'F. and the minimum 47°F. For the remain- 

 ing period (twenty-six days) the maximum was 110°F. and the 

 minimum SO'^F. 



Experiment No. 33. 



Fifty pupae of unknown ages, collected on November 21st, were- 

 placed in a loose ball of sheep's wool about f in. in diameter in a 

 small, thin muslin bag, which was then tied to a post on the quad-^ 



