Packard.] 136 [Nov. 19, 



November 19, 1873. 



The President in the chair. Seventy-nine persons present. 



The following papers were read : — 



On the Transformations of the Common House Fly, with 

 Notes on allied Forms. By A. S. Packard, Jr., M.D. 



It is not a little strange that the history and transformations of the 

 common House Fly are so little known. There is a vague idea that 

 it breeds in the manure of stables, but no one in this country has in- 

 vestigated its habits, and even Dr. Harris, by describing our common 

 species under a separate name, seems to indicate that ours is not the 

 common House Fly of Europe. In Europe, even, but little attention 

 has been given to its habits. They are mentioned only in three 

 works, one of which (by Bouche) was published during this century, 

 with figures so poor and inadequate as to be actually misleading. 



Having been fortunate enough to find the larvae of this species in 

 large numbers and then in inducing the adults to lay eggs in great 

 abundance at our own pleasure, as it were, we make the attempt to 

 clear up the history of the development and transformations of 

 Musca domestica Linn. 



Bibliography. After Linnaeus had described this species as the 

 Musca domestica, DeGeer 1 was the first to satisfactorily describe its 

 transformations. He says that the larva lives in warm and humid 

 dung, but does not say how long it lives in the egg, larva, or pupa 

 state. He gives a good description of the larva, stating that its pro- 

 thoracic stigma ends in six divisions, and adds, " Ces larves, que sont 

 absolument sans pattes, n'ayant pas meme ces mamelons charnus 

 qu'on observe a celles de la viande [Musca carnaria] et de quelques 

 autres especes, se sont des cocques de leur propre peau, mais qui 

 n'ont rien de particulier a onrir et les mouches en sortent peu de jours 

 apres (p. 78, Tome 6, 1776). 



In 1834 Bouche 2 described the larva, remarking that it lives in 



1 Carl De Geer. M^moires pour servtr a l'histoire des Insectes. Stockholm, 4°. 

 1752-'78. 



2 P. Fr. Bouche\ Naturgeschichte der Insekten, etc. Berlin, 1834. 12°. The 

 third work we have alluded to is by Keller; Geschichte der geineiner Stubenfliege, 

 1764 and 1796. This last we have not seen. 



