DIPTERA OF MINNESOTA. 21 



mal, the child, as well as man, play; the sense of strength, and the higher 

 sense of freedom derived from strength, give rise to the joy of playing." 



It was evidently the intention of our predecessor, Dr. Lug- 

 ger, to publish a monograph on the Dipfcra of Minnesota, as he 

 had on the four orders, Orthoptcra, Colcoptcra, Lepidoptera, and 

 Hcmiptcra, before death put an end to his valuable work. We 

 found some drawings and other evidence of this intentiori on his 

 part, and it seemed quite fitting and a mark of respect to the mem- 

 ory of him who stood for so much in Entomology to endeavor to 

 complete the work he undoubtedly had in mind. There is, further, 

 a demand on the part of our agriculturists, stock raisers and others 

 for a report on the pests which occur in this group, with remedies 

 for the injuries caused by them, or means to prevent such injuries. 



For four years, therefore, we have been accumulating specimens, 

 drawings and data with that end in view. Dr. Lugger was no man 

 for notes. He left absolutely no data in this group, and this fact 

 has added materially to the difficulties of the work. It must be 

 acknowledged, too, that the labor involved in properly depicting this 

 one group alone, as it occurs in Minnesota, is so great that we feel, 

 in its presentation, we have fallen short of the ideal cherished by 

 us at its first conception. Yet, although huiubled by this realiza- 

 tion, we present this report on the "Diptera, or Two-Winged 

 Flies oi? Minnesota," without an apology, hoping that through 

 means of the excellent illustrations and the two colored plates the 

 citizens of the state may be able to recognize the leading pests, and 

 also beneficial insects which occur in this group, and that the 

 student who is interested in the flies of Minnesota may be helped 

 in his study. In fact, with this latter end in view, we have so 

 arranged the report that it may, like other similar publications from 

 this department, which have been in great demand, serve a double 

 purpose, namely, while it is primarily a bulletin on injurious flies, 

 it can at the same time be used in schools, illustrating, as it were, 

 one department of rural school agriculture. At the end of the 

 book will be found a complete index, together with a special index 

 of two-winged pests and remedies therefor. 



In accomplishing this work we have been hampered by lack 

 of data, as mentioned above ; in some cases by erroneous labeling 

 of specimens which we found in the collection, notably in the family 



