INTRODUCTION. l x 



knowledge of the taxonomy of the diptera, may be eon- 

 fined, for the most part, to those groups which have been 

 monographed, with full descriptions of genera and spe- 

 cies, and, if possible with numerous illustrations. Refer- 

 ences to the more important papers of each family will 

 be found in Aldrich's catalogue. 



Long before the student has reached the dignity of 

 'independent research', he will have learned who the 

 masters of dipterology are ; who have shown the greatest 

 acumen in the discernment and use of classificatory char- 

 acters. It will not be invidious to distinguish above all 

 others Schiner, L,oew and Osten Sacken as writers who 

 can not be too faithfully studied, too closely followed. 

 Not that they are infallible; none are. Indeed an error 

 of a master is often more instructive than the masterpiece 

 of a dullard. One must learn the values of characters in 

 classification before he can be successful in instructing 

 others, or in making his discoveries known. And this 

 knowledge can only be acquired by long and faithful 

 study of living things and due reflection thereon. The 

 narrow systematic specialist is looked upon somewhat 

 askance by modern biologists, and rightfully too, but I 

 have no hesitation in saying, and it is the experience of 

 many years of study in different branches of natural his- 

 tory, that the right kind of systematic work calls for the 

 highest scientific powers of the student. I am aware that 

 some narrow specialists in other departments of science 

 will take exception to this statement, but I believe it and 

 say it for the encouragement of those who may be dis- 

 suaded from the earnest study of such creatures by the 

 flippant remark of the shallow minded. But a mere col- 

 lector of specimens, one who finds enjoyment in getting 

 the largest number and arranging them in serial form in 

 his cabinet is not necessarily a scientific student, though 

 he may have a very pleasant and useful pastime; his la- 



