18 



sible 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 development 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 impossibility 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. 



Wednesday Afternoon Session. 



The Club met for an hour, at 5 o'clock, p.m., in one of the rooms of the Massachusetts 

 Institute of Technology, a large and commodious building, which was almost entirely 

 given up to the work of the Association. 



The short time at the disposal of the Club was occupied by the continuation of the 

 Rev. H. C. McCooks lecture on the Honey-ants of the Garden of the Gods, Colorado ; the 

 first portion of which he delivered on the previous afternoon. At its conclusion, some 

 remarks were made by Prof. Cook and others, on birds versus insects. 



Thursday was devoted by the the Association to a visit to Cambridge. Many of the 

 Entomologists took the opportunity of visiting the rooms of the Cambridge Entomological 

 Club, where they were received by Mr. B. P. Mann, the Secretary. 



Friday Afternoon Session. 



The Club met in their room in the Institute of Technology at 4 o'clock p.m., Mr. A. 

 R. Grote, Vice-president, in the chair. 



Dr. LeConte moved that, owing to a resolution passed at the general session of the 

 Association that morning, the Entomological Club do now organize as a permanent Sub- 

 section of the Association. He proceeded to congratulate the Club on the honour thus 

 conferred upon it. It was due to the importance of the subject and the large attendance 

 of Entomologists, no less than to the number of interesting papers offered for their 

 discussion. The resolution was unanimously adopted, and the Club at once organized as 

 a Sub-section with the officers elected on the first day of meeting. 



Mr. E. Burgess, of Boston, gave an account of the structure of the mouth organs of 

 Butterflies, describing especially and illustrating with diagrams on the black-board, the 

 proboscis, etc., of the Archippus. Remarks were made upon the paper by Dr. Hagen and 

 Messrs. Mann, Cook and Riley. 



Dr. Hagen read a paper on the anatomy of Prodoxus decipiens, in which he confirmed 

 Mr. Riley's statements. 



Prof. Fernald read a paper on Phoxopteris anyulifasciana, a small tortrix feeding 

 upon clover. 



Mr. O. S. Wescott, of Racine, Wis., gave by request an account of a moth trap for 

 collecting insects by light, which he had employed with much success. Dr. Hoy and Mr. 

 Mann also described insect traps that they had found useful. 



Mr. Westcott gave an account of the mode of building its web by a geometrical 

 spider, and stated that the insect when forming the concentric lines across the rays 

 measured the distance from the next parallel line by means of its second right fore-leg 

 before attaching the thread to the ray. 



Prof. Cook, in answer to a question, stated that he had found a mixture of honey 

 and beer equally efficacious with the ordinary mixture for sugaring. 



Mr. Grote remarked that he had found the Colorado potato • beetle feeding upon a 

 large cultivated variety of Datura, and feared that it would probably soon prove a serious 

 enemy to the tobacco plant, another member of the family Solanacece. 



