THE CANADIAN ENTOMOLOGIST. 17 1 



on '-'the Pterophorid?e of California and Oregon." He then proceeded 

 to read a paper on the Classification of Tortricidas, illustrating his remarks 

 by some wings prepared for the microscope. These slides, which beauti- 

 fully exhibited the venation of the wings, were mounted with glycerine 

 boiled gently over the lamp; the wings were bleached by Dimmock's process. 



Dr. H. A. Hagen, of the Museum of Comparative Zoology, Cambridge, 

 Mass., read a paper on the importation of the Hessian Fly. The generally 

 accepted theory, from which the insect derives its common name, is that 

 the insect was brought from Europe to America about a century ago in 

 the straw used for bedding by the Hessian troops employed by the British 

 Government in the war of the Revolution. This theory Dr. Hagen rejects, 

 and in a sketch of the history of the movement of these troops, he showed 

 that the lapse of time during their transportation was considerably greater 

 than that of the term of the normal development of the fly from the egg. 

 He stated that there was some evidence of the existence of the fly in 

 America before the arrival of the Hessian troops, and that it was unknown 

 in Central Europe till recently ; there was, however, some evidence that 

 it may have appeared in certain places on the Mediterranean Coast at an 

 earlier period. He even thought it possible that the fly might have been 

 imported from America into the Mediterranean region of Europe by 

 American trading vessels. His conclusions, as stated in a long and very 

 interesting paper, in which he quoted many German and British official 

 records, may be summed up briefly as follows : i. It is impossible that the 

 fly could have been imported by Hessian troops, as proved by the historical 

 records. 2. The fly must have been in America long before the arrival of 

 the Hessian troops. 3. The fly was not known in Germany before 1857, 

 and is probably an indigenous American insect. 



Prof. Riley stated that he had so often noticed a retardation of develop- 

 ment in insects, that he should not be surprised if this had been the case 

 with the Hessian fly, when imported. Again, that the "flax-seed state" of 

 this insect lasts so long that it might have crossed the Atlantic during that 

 phase of its existence. 



Dr. Hagen replied that Dr. Asa "Fitch had already proved the impossi- 

 bility of this. 



Prof. Riley accepted the theory that the fly is indigenous to America, 

 and Dr. Hagen stated that he believed that it is indigenous to both 

 Europe and America. 



The meeting then adjourned. 



