(58) 



498 C. GORDON HEWITT. 



was the next to study the development and working in the 

 United States of America at Salem, Mass., he found that 

 the larvae emerge from the eggs twenty- four hours after 

 deposition; the times taken by the three larval stages for 

 he found that there were two larval ecdyses were : first, 

 about twenty-four hours ; the second stage, he thought, was 

 from twenty-four to thirty-six hours; and the third was pro- 

 bably three or four days ; the entire larval life being from 

 five to seven days. The pupal stage was from five to seven 

 days, so that in August, when the experiments were carried 

 on, the time from hatching to the exclusion of the imago 

 was ten to fourteen days. Taschenberg (1880) incorporates 

 the work of Keller and Bouche, and does not appear to add 

 anything of importance to the facts already mentioned. He 

 states that the female flies deposit their eggs in damp and 

 rotting food-stuffs, bad meat, broth, slices of melon, dead 

 animals, cesspools, and manure-heaps. He further says that 

 they have 'also been observed laying their eggs in spittoons 

 and open snuff-boxes. With reference to the last statement, 

 I find that the larvae will feed on expectorated matter mixed 

 with a solid substance, such as earth, if they are kept warm, 

 though they cannot feed on salivary sections merely ; but, 

 although flies might im providently deposit their eggs in an 

 open snuff-box, the larvae would soon perish on hatching on 

 account of the dry conditions. 



Howard (18961906) first studied the breeding habits of 

 the fly in 1895 in Washington, U.S.A., and he described 

 them in 1896, and more fully subsequently. He found that 

 they could be rarely induced to lay their eggs in anything 

 but horse-manure and cow-dung, and that they preferred the 

 former. The periods of development he found were as 

 follows : from the deposition of the egg to the hatching of 

 the larva about eight hours ; the first larval stage one day ; 

 second larval stage one day ; third larval stage that is, from 

 the second ecdysis to pupation three days, and the flies 

 emerged five days after the pupation of the larvae, thus making 

 the whole period of development about ten days. The same 



