122 THE CANADIAN ENTOMOLOGIST. 



concede that the insect was introduced some time prior to the revolution ; yet that its 

 introduction about that time must be accepted, because Hagen's arguments to the 

 contrary were not supported by [sufficient] evidence." 



" Prof. Riley further remarked that he had referred to these conflicting views oi 

 leading writers as to the original source and time of introduction of the insect into 

 America, not so much to foreshadow the future conflict of opinion on similar points in 

 England, as to bring out this important fact as a warning to hasty generalisers, viz., that 

 the arguments of Wagner, Hagen, etc., against its introduction into America, were 

 inherently weak from the biologic side. They are based on the average or normal period 

 of summer development of about seven weeks from egg to adult, and ignore the impor- 

 tant bearing of exceptional retardation in development 'whereby the puparia of one summer 

 remain talent and only give forth the flies in the spring or early summer of the ensuing 

 year. This fact, recognized by Harris (1852), Prof. Riley said he had evidence of 

 in America in garnered straw, and it was proved by Wagner himself to have occurred in 

 Germany in field stubble. It was more apt to occur, however, in straw kept dry and 

 packed than in stubble or exposed straw, and is in keeping with many other similar 

 cases of retarded development in insects, some remarkable instances of which he called 

 attention to before the American Association for the Advancement of Science in 188 1. 

 It destroyed Hagen's main argument, rendered the introduction of the species possible 

 at almost any season, and made its introduction to America by the Hessians, who left 

 Portsmouth, April 7th, and landed June 3rd, 1777, on Staten Island, quite probable and 

 plausible from biologic grounds." 



For the purpose of the present communication, it is not necessary to 

 go into the other arguments which Hagen has brought forward to relieve 

 the Hessians of whatever onus attaches to their accidental introduction of 

 this insect : the more important are, (1) that there was no Hessian Fly 

 in Germany at the time, and (2) that the Hessian troops did not carry 

 straw from regions in which it did occur. At this late day it would be 

 folly to attach too much importance to these negative deductions, where 

 there are so many possibilities of their both being erroneous in fact. The 

 evidence as to the introduction and spread of the insect in this country 

 is of a so much more clear and positive nature that it off-sets such nega 

 tive deductions. With the exception of Mr. Phillips's positive statements, 

 there is only one other recorded statement that would seem to indicate 

 that the Hessian Fly was known in the United States prior to the land- 

 ing of Hessian troops. This is a statement quoted by Fitch, of Judge 

 Hicock, of Lansingburg, N. Y., who says (Memoirs of Bd., of Agr., n, 

 p. 169) that a farmer named Jas. Brookins had informed him (Hicock), 

 that upon his first hearing of the alarm upon Long Island, in the year 

 1786, he (Brookins) detected the same insect in the wheat growing on 

 his farm in Lansingburg. Fitch remarks in parenthesis, "doubtless 1776 



