As the readers of the Canadian Entomologistare aware Dr. H. A. Hagen has argued at length to the effect that the Hessian Fly was, first not imported by the Hessian troops; secondly, that it was not imported from Europe at all, and that it is an indegenous North American insect. In the Third Report of the U.S. Entomological Commission, Dr. Packard has an extended article upon the Hessian Fly, and while he alone is responsible for the general position there taken on this subject, we discussed the matter together, and the views there presented are substantially those which I held at the time, as it was Dr. Packard's desire to arrive at an impartial judgement.