98 Ceroid F. Hill: 



Experiment A'o. 21. 



Ten pupa4e of unknown ages, collected on August 17th, were kept 

 on moist sheep-pen sweepings and incubated at 18°C. to 28°C. Two 

 young flies emerged on tenth day, one on seventeenth day, three on 

 nineteenth day, two on twenty-second day, one on twenty-third day, 

 and one on twenty-si?:th day. 



Thus 100% of these pupaei produced young flies ten to twenty-six 

 days after their removal from tlie host. 



Experiment ^o. 22. 



Thirty-five pupae, known to be less than six days old, were col- 

 lected on September 19tli, and kept on moist sheep-pen sw^eepings in 

 an incubator at temperatures ranging from 26°C. to 32°C. Two 

 young flies em)erged on the twelfth day, two on fourteenth day, two 

 on fifteenth day; six on sixteenth day; five on nineteenth day; two 

 on the twentieth day; and one on the twenty-first day. 



Thus 57% of the pupae remained viable, and produced young flies 

 within twelve to twenty-one days of. their removal from the host. 



Experiment No. 23. 



Thirty pupae of unknown ages v.ere collected on August 30th, 

 and placed on dry sh,eep-pen sweepings in an incubator at a tem- 

 perature of 22 °C. Two young Louse-flies emerged on fourth day, 

 three on eleventh day, two on eighteenth day, one on nineteenth day, 

 one on twentieth day, and one on twenty-tliird day. The remaining 

 twenty-one pupae died. 



Thus 30% of the pupae remained viable and produced young flies 

 Avithin two to twenty-three days of their removal from the host. 



Experiment No. 2Jf.. 



Thirty pupae of unknown ajges were collected on August 30th, 

 placed on dr^j sand, and incubated at a temperature ranging from 

 18"C. to 28°C. One young emerged each day from the fourtli to the 

 sixth day, two flies emerged on seventh day, two on eleventh day. two 

 on fourteenth day, seven between tlie fifteenth and eighteenth days, 

 two on nineteenth day, and one on twenty-first day. The remaining 

 ten died. 



Thus 60.6% of the pupae remained viable, and produced young 

 flies within four to twentv-one days of their removal from the host. 



