102 Geralil F, Hill: 



four on the thirty-fourth day, two on the thirty-seventh day, one- 

 on the thirty-ninth day, and one on the forty-second day. The re- 

 maining fifty pupae were found to be dead on February 27th. 



Thus 72% of the pupae remained viable, and produced youn^ fiies 

 in one to fortv-tw^o days after their? removal from the host. 



Summary and Observations. 



The results of these eighteen experiments to determine the 

 viability of the pupa when removed from the host are summarised 

 in the following tabulated statement : — 



VIABILITY OF THE PUPA. 



Ccriditions under which pupae were kept. 



On moist sheep-pen sweej^in^s in incubator - 

 On dry sand in incubator . . . - 

 On moist paper in incnbator - - - 



On Avool in tin in laboratory . . _ 



On dry sand in incubator - 

 On moist sheep-pen sweepings in incubator - 

 In dry petri dish in incubator . _ . 

 In wool on post out of doors - - - - 

 On dry sheep-pen sweepinos in incubator 

 On moist sand in incubator - - - - 

 On sand on lawn ------ 



On sand on lawn 



On dry sand in incubator - - - - 



On sand on lawn 



On sand on lawn ------ 



On moist sand in incubator - - - - 



On moist earth in cellar - . - _ 

 On dry earth in cellar 



1/ 

 £ 6 



Ran<,''e of 



Temperature 



Fahr. 







be 



ir 



CS 



c 



I 



a. 



3 r- >. 



m 



21 



- G4.40-82.4O 



10 



. 



26 



. 



100. 



25 



- 71.6 



3 



- 



32 



- 



82.6 



19 



- 93.2 



18 



- 



19 



- 



75. 



36 



- (50-90 



1 



- 



42 



- 



72. 



24 



- 64.4-82.4 - 



4 



- 



21 



- 



60.6 



22 



- 78.8-89.6 - 



12 



- 



21 



- 



57. 



20 



- 91.4 



7 



- 



11 



- 



42.8 



33 



- 47.0-84.0 - 



3 



- 



27 



- 



31.5 



23 



- 71.6 



4 



- 



23 



- 



31. 



27 



- 71.6 



12 



- 



25 



- 



13.3 



29 



- 44.0-68.0 - 



6 



- 



U 



- 



6. 



30 



- 34.0-86.0 - 



22 



- 



34 



- 



4. 



2fi 



- 96.8 



1 



- 



— 



- 



4. 



31 



- 34.0-86.(' - 



— 



- 



— 



- 



0. 



32 



- 47.0-84.0 - 



— 



- 



— 



- 



0. 



28 



- 96.8 



— 



- 



— 



- 



0. 



34 



- 50.0-59.0 - 



— 



- 



— 



- 



0. 



35 



- 50.0-59.0 - 



— 



- 



— 



- 



0. 



Note — In all experiments in which the pupae wore kept in the incubator a certain 

 amount of humidity was provided by placinj^ a small petri dish of water on 

 the lower shelf. 



It will be seen from this statement that under the most favourable 

 conditions 100% of the pupae removed from the host are capable 

 of developing into young Louse-flies. This high percentage of 

 emergences Avas obtained in one experiment in which the pupae were 

 placed on moist sheep-pen sweepings and kept in an incubator at 



