TWO PRINCIPAL WORKS OF ROBINEAU-DESVOIDY 
189 
will understand how much labor his genera Tachina and An- 
thomyia must have cost him. Without allowing myself the 
slightest criticism of a work so laborious and containing so much 
of new material, I will merely observe that I have too often fol¬ 
lowed a different course, and therefore cannot be accused of having 
worked according to his methods. Mr. Meigen excels in the art of 
describing Diptera, nevertheless it is certain that the possibility 
of establishing a perfect synonymy, based upon his characters and 
descriptions, may perhaps not exist (‘ n’existe peut-etre pas ’). I 
merely describe species which I have seen and studied. This author 
mentions many that I do not know, and about which, for fear of 
error, I prefer to remain silent.” 
Rob.-Desvoidy was not the only one to criticize Meigen’s descrip¬ 
tions ; there is a very instructive passage in Loew’s work on the 
Asilidae (Linnaea Entomoloyica , Yol. Ill, 1848, p. 410-413), 
about the difficulties he and Zeller met with in attempting to recog¬ 
nize species of Asilidae and Bombyliidae in Meigen’s descriptions. 
Even specimens labelled in Meigen’s handwriting are not implicitly 
to be trusted, because he sometimes did not recognize his own 
species. This is not intended as a reproach to Meigen, but merely 
as an expression of the difficulty of the subject. 
As Rob.-Desvoidy’s Myodaires is the principal work which, 
hitherto, has been in use among dipterologists, and as his reputation 
has been principally grounded upon this volume, I have thought 
it worth while, in the preceding pages, to publish the result of my 
investigations of the circumstances under which it was prepared, so 
far as the sources were accessible to me. But Rob.-Desvoidy con¬ 
tinued his indefatigable researches upon Diptera for twenty-five 
years longer, up to his death; as he said himself: “ Je crois que je 
mourrai en loupant un diptere” (“Histoire Xaturelle des Dipteres,” 
1863, p. 33). He left an almost finished manuscript, which he con¬ 
sidered fit for publication (ibid ., p. 44), and which was published 
six years after his death. 11 is own opinion concerning the relation 
of these two works is expressed in the following terms : — 
“Thus I shall enjoy the happiness of having been twice the father of the 
same work. The ‘ Essai sur les Myodaires’ (1830) will recall my first 
flights (‘ elancements ’) in the field of science, my warm aspirations towards 
