LOEW’S FIRST VOLUME OF THE “MONOGRAPHS” 
47 
Winnertz’s work on Cecidomyiidae and Mycetophilidae has found 
many successors, but that on Ceratopogon has not. A great deal 
remains to be done for the classification of this group, so rich in 
European and exotic forms, some of which are remarkable for the 
great variety of their general organization, as well as for the mani¬ 
fold modes of their transformation. But it will be difficult for any 
future worker in this branch to surpass the genius and the consci¬ 
entiousness of Winnertz ! 
YII REMARKS, HISTORICAL AND CRITICAL, CONCERNING 
LOEW’S FIRST VOLUME OF THE MONOGRAPHS OF 
NORTH AMERICAN DIPTERA, WASHINGTON, 1862 
The first volume of the “ Monographs of North American Dip- 
tera ” begins with the chapter On the terminology of Diptera , p. xi- 
xxiv, followed by a Sketch of the systematic arrangement of Diptera, 
p. 1-48. These papers were written by Loew at the special 
request of Professor Henry (of the Smithsonian Institution), who 
wanted some kind of Introduction to Dipterology at the head 
of the intended series of the Monographs. This very natural 
request found Loew utterly unprepared. In a letter to me (July 
25, 1860), he said: “ I undertook this work with fear and terror 
(‘Furcht und Grauen’), because the existing Systems are not 
acceptable, and the difficulties of the introduction of a new one can 
be understood only by those who know the lamentable state of 
things we are in (‘ wie alles hier noch im Argen liegt ’). Just by 
such a work one may expose oneself to very disagreeable criti¬ 
cisms! For a long time I have been hesitating whether I should 
not altogether get rid of this, to me most repulsive, task (‘ mir 
sehr widerwartige Arbeit ’). Now, after much effort, the ‘ Opus ’ 
is completed (‘ das Opus ist nun fertig ’). That I have learned 
much during this work is certain; whether others will learn much 
from it — is doubtful (‘ ob auch andere daraus viel lernen werden, 
zweifelhaft ’). As an unmistakable result I have obtained the 
confirmation of my old convictions : (1) That the venation must 
be maintained as the chief basis of classification; (2) That the 
