■i.)() The Manure Heap and the Housc-Fly 



having behind it a huge manure shed in which manure is stored in 

 larfie tiuantities. Tlie heaps used in this and other experiments at the 

 farm were trenched and enclosed precisely as already descriheil, and 

 were placed some 20 yards from the stable door. Upon Hea]i 1 was 

 thrown a barrow load of fresh horse manure every day, taken direct 

 from the stable adjoining. The heap was started on June 28th and 

 covered in on July I'lth, and remained covered till August 1th. From 

 it there hatched out only 26 flies, of which 16 were CaUiphom eii/lhro- 

 cephala, 5 Chortophila cilicritra, and 3 Fannia canicularis. Two others 

 were small flies of undetermined species. No examples of M. domestica 

 were obtained. The preponderance of " Blue bottles ' is rather remark- 

 able, and may have been due to a dead vole or some other small animal 

 having got into the heap. Half nf them came from the trench traps. 

 The highest tem])orature recorded for this heap was about 50° 

 though it was probably higher at some time during my temporary 

 absence owing to a slight accident. 



Experiment Vl. Close to the heap used for Experiment ^' some 

 compacted mixed manure was trenched and enclosed as before. This 

 licaj) was covered in about Julv 1 1th after being open to infection for 

 1.") daws. It remained covered til! .\ugust !)th. The highest temperature 

 recorded was 50". During the period named the following 57 Hies were 

 obtained : 



Eristulis temis L. ... ... 3 



SloiHO.rijs cakilruns L. ... ... 2 



Sarfpis ciiprarius L. ... ... 10 



Hydrotaea armipes ¥. ... ... 21 



Fannia ranirularis L. ... ... 17 



Cordj/lurid i<\). '. ... ... ... 1 



Of the above only two came froiu tlic tiencli. Ixitli liring E. lena.r. 



E.rperiinenl VII. .\ lieaj) corresponding to that used in ExixM'iment 

 VI was made near the farm buildings. Mixed manure was l.iid on it 

 light instead of compacted. The hea)) was enclosed about .luly Mth 

 after being open to infection for 15 days, and remained closed till 

 August 12th. From this heap the following flies emerged: 

 Op/ii/ni U'Kcoslonia W. ... ... 36 



Stomoxi/s calcilrans L. ... ... 4 



Sargu.s cvprariiis \j. ... ... 13 



Chorlopliilii rilirrnni \{(\\. ... 37 



Chrysomijza demandata F. ... 6 



Fannia canicvlaris L. ... ... 3 



