4 Hewitt, Life-history of the Common House Fly. 



so that, given a spell of really hot weather we might have 

 flies developing in a fortnight or even less, in England. 

 Packard and Howard found that the time taken from the 

 deposition of the egg to the emergence of the fly was 

 about ten to fourteen days. 



As this communication is only of a preliminary nature 

 further details of the development, together with the 

 results of further experiments, which it is my intention 

 to make, will be incorporated in the account of the larva 

 which will be published later. 



LITERATURE. 



'74. Packard, A. S. " On the Transformations of the Common 

 House Fly, with notes on allied forms." Proc. Boston 

 Soc. Nat. Hist., vol. 16, p. 136 — 150, 1 pi. 



:02. Howard, L. O. " House Flies " (" The Principal House- 

 hold Insects of the United States," by L. O. Howard 

 and C. L. Marlatt). United States Department of 

 Agriculture, Washington. Division of Entomology, 

 Bull, no. 4, N.S. Revised ed., p. 43 — 47 and figs. ; 

 and Circular, no. 35, 2nd Series, p. 1 — 8 and figs., 1898. 



De Gee, R. first described the transformations of M. domestica in 

 his " Memoires pour servir a l'Histoire des Insectes." 

 8 vols. Stockholm, i752-'78, but did not give the time 

 taken by the various stages. 



