DIPTERA, 425 



begin to lay their eggs, in which business they are occupied for 

 several weeks. The following interesting account of the manner 

 in which this is done was written by Mr. Edward Tilghman, of 

 Queen Ann County, Maryland, and was published in the eighth 

 volume of " The Cultivator," in May, 1841. "By the sec- 

 ond week of October, the first sown wheat being well up, and 

 having generally put forth its second and third blades, I resorted 

 to my field in a fine warm forenoon, to endeavour to satisfy my- 

 self,, by ocular demonstration, whether the fly did deposit the 

 egg on the blades of the growing plant. Selecting a favorable 

 spot to make my observation, I placed myself in a reclining po- 

 sition in a furrow, and had been on the watch but a minute or 

 two, before I discovered a number of small black flies alighting 

 and sitting on the wheat plants around me, and presently one set- 

 tled on the ridged surface of a blade of a plant completely within 

 my reach and distinct observation. She immediately began de- 

 positing her eggs in the longitudinal cavity between the little 

 ridges of the blade. I could distinctly see the eggs ejected from 

 a kind of tube or sting. After she had deposited eight or ten 

 eggs, I easily caught her upon the blade, and wrapped her up in 

 a piece of paper. I then proceeded to take up the plant, with 

 as much as I conveniently could of the circumjacent earth, and 

 wrapped it all securely in a piece of paper. After that 1 con- 

 tinued my observations on the flies, caught several similarly oc- 

 cupied, and could see the eggs uniformly placed in the longitudi- 

 nal cavities of the blades of the wheat ; their appearance being 

 that of minute reddish specks. My own mind being thus com- 

 pletely and fully satisfied as to the mode in which the egg was 

 deposited, I proceeded directly to my dwelling, and put the 

 plant with the eggs upon it in a large glass tumbler, adding a little 

 water to the earth, and secured the vessel by covering it with 

 paper so that no insect could get access to the interior. The 

 paper was sufficiently perforated with pin holes for the admission 

 of air. The tumbler with its contents was daily watched by 

 myself to discover the hatching of the eggs. About the middle 

 of the fifteenth day from the deposit of the eggs, I was so fortu- 

 nate as to discover a very small maggot or worm, of a reddish 

 cast, making its way with considerable activity down the blade, 

 54 ^ 



