THE CECIDOMYIA CULMICOLA. 583 



cends the straw on the outside, where it attaches itself 

 firmly, and awaits its change; the outer skin becomes the 

 puparium. In the pupa or flax-seed state, it closely resem- 

 bles the O. destructor. Should the culm of the wheat be- 

 come prematurely hard before the worm has finished feeding, 

 as is often the case, the insect will remain imprisoned for 

 life, passing through its changes inside the straw, and there 

 perish without the power to escape, unless some accidental 

 passage be made for it. I have liberated," she adds, " hun- 

 dreds with my penknife, and thousands make their escape 

 after the grain has been reaped and carried into the barn. 

 When the insect is thus unnaturally retarded, the time of 

 its perfect development is uncertain " ; and she has " found 

 them on the straw, and in spiders' webs, from June until 

 September." 



Four of the specimens sent to me by Miss Morris were 

 males. Another subsequently received was a female. The 

 former were not more than half the size of the latter, and 

 indeed were smaller even than the wheat-fly, which they 

 seem somewhat to resemble. The female was evidently 

 much darker-colored originally than the males. These in- 

 sects were genuine specimens of Cecidomyia, and apparently 

 of a different species from the Hessian fly. The condition 

 of the specimens, which had suffered by compression and 

 by being badly preserved, was such, that an accurate com- 

 parison and description of them could not be made. I under- 

 stand that the species has disappeared from Germantown 

 and the vicinity, and hence no opportunity for obtaining 

 living or recent specimens has occurred since the year 1843. 

 Various means have been recommended for preventing 

 or lessening the ravages of the Hessian fly ; but they have 

 hitherto failed, either because they have not been adapted 

 to the end in view, or because they have not been univer- 

 sally adopted ; and it appears doubtful whether any of them 

 will ever entirely exterminate the insect. It is stated in 

 the before mentioned Report of the Philosophical Soci- 



