J. E. M. Mellor 81 



Henri Fabre found th'dt Sarcophaga carnaria could tiavcivse a coluniii 

 of sand six inches hioh in 15 minutes; and in an experiment, i)i which 

 he placed lots of 15 pupae of CaUiphora at the bottom of large glass 

 tubes, which were then filled with different quantities of sand, found 

 that from those pupae covered with 



G cm. (2-;}4") of sand 14 out of 15 flies reached the surface 

 12 cm. (4-68") „ 4 



20 cm. {7-8") „ 2 „ „ „ 



GO em. (23-4") .. 1 



Hewitt (1915) found pupae of M. domestica, from which flies had 

 successfully emerged, 24 inches below the ground in light soil. 



Graham-Smith (1916) made the following observations on burial of 

 infested material: (1) " On July 7th a large piece of sheep's lung contain- 

 ing some eggs and very small larvae was buried to a depth of 1| feet, 

 and the earth well packed down. The earth was further trodden down 

 on July 9th. On July 12th the material was exhumed and numerous 

 large, apparently healthy, larvae were found in it." (2) " On September 

 Ith the bodies of six guinea-pigs were exposed. On the same day one of 

 the carcasses with eggs in the mouth and on the hair was buried to a 

 depth of one foot in an earthenware pipe sunk vertically in the ground. 

 A little earth was placed above the carcass and packed down tightly, 

 and the process repeated till the pipe was full. The top of the pipe was 

 sealed with an earthenware saucer. The other carcasses containing larvae 

 of various sizes were similarly buried on September 8th, 10th, 11th and 

 14th. On September 26th full fed larvae and pupae were noticed just 

 below and on the surface of the earth in all the pipes. Blow-flies began 

 to emerge simultaneously from all the pipes on October 17th, and large 

 numbers were caught up to October 29th, and smaller numbers up to 

 November 15th. These observations show that larvae emerge from eggs 

 and thrive in buried carcasses, and that they are able to make their way 

 to within a short distance of the surface where they pupate. And that 

 the burial of a carcass does not prevent flies emerging from eggs already 

 laid, but only limits the production of flies by preventing later batches 

 of eggs from being deposited." 



The greatest depth tested by Fabre and by Graham-Smith was 23-4 

 inches and 18 inches respectively. 



During May 1917, a hole ABCD (Fig. 6) about 4 f t x 4 ft x 4 f t 6 in. 

 deep with an approach trench GCEF was dug in light loam soil. The 

 floor was covered with sand to a dej^th of two inches to enable the 



Ann. Biol, vi G 



