11. Ei;i'KixuHA.M 449 



Experiment III. Mixed material, principally horse and cow manure, 

 was obtained from a neighbouring farm and placed on a trap at the 

 laboratory prepared as already described. It was then well trodden 

 down so as to represent the compacted form of storage. This was 

 completed on June 29th. On July 1st the temperature at centre was 

 42\ on July .5th -55°. and on July 8th 58°. It subsequently fell on 

 July 21st to 40°, but rose again two degrees on July 26th. The heap 

 was covered in on July 12th, and remained closed till August 5th. 

 During that time the following flies were trapped therefrom : 

 Eristalis tenax L. ... ... 8 



Stomoxys calcitrans L. ... ... 8 



Sargus cuprarius L. ... ... 15 



Chrysoiin/za doiiandata F. ... 2 



Fannia ratiiciilaris L. ... ... 6 



Choriophila cilicnira Rdi. ... 9 



There is a complete absence of M. doiiieslica, the material having 

 failed to become infected either at the laboratory or at the farm whence 

 it was obtained. Most of the flies came from the heap direct. 



Exferuiient IV. A heap of material similar to that used in E.xperi- 

 ment III was established on June 29th at the laboi'atory. The manure 

 was however in this case laid light without any treading. On July 1st 

 the temperature was 57°, on the 5th 60°, on the 8th 38°, on the 21st 26°, 

 and on the 26th 35°. The heap was covered in on July 12th, and 

 remained covered till August 5th, during which period the following 

 flies were obtained : 



Eristalis tenax L. ... ... 13 



Stomoxys calcitrans L. ... ... 9 



Chortophila cilicnira Rdi. ... 14 



Scatophaga stercoraria L. ... 4 



Sargiis cuprarius L. ... ... 2 



Fa)uiia canicnlaris L. ... ... 3 



This heap produced 45 flies as against the 48 in Experiment III. 

 All but three came from the heap direct. The total absence of 

 M. domesfica is again noticeable. 



Experiment V. An experimental heap was established near the 

 farm buildings belonging to the Rothamsted Experimental Station, and 

 over a mile from the laboratory. The position of this and other 

 heaps referred to as "at the farm" scarcely requires illustration. With 

 the exception of two small cottages some 70 yards distant, there are 

 no dwellings near these buildings, which include a stable for horses 

 Journ. of Agrio. Sci. Tn 30 



