( xlvi ) 



posteris relinquendwm. On voit que Fabricius ne pouvait plus 

 faire avancer la science, et qu'il sentait la necessite de larges 

 innovations ; mais il ne se doutait pas encoi-e de I'immensit^ 

 de I'heritage laisse deiri^re lui." 



An enormous scientific improvement has developed in the 

 improved labelling of species both as to locality and date, 

 and also as to the authorities for the nomenclatui^e of the 

 specimens in difficult cases. It is impossible that too much 

 care can be taken in such matters. We know now by ex- 

 perience from the past the trouble which incorrect labels of 

 locality may cause, and we also know the immense loss of 

 value attached to interesting specimens which are without a 

 history. Although I hate the need of reference to type 

 specimens, because if the description is adequate no reference 

 to a type should be necessary, and if the description is in- 

 adequate it should not hold priority over the next adequate 

 description, yet I know that the examination of a well- 

 authenticated type will often open a student's eyes to the 

 fact that a mistake has been copied from author to author 

 which a close examination of an original description would 

 have shown to be unpardonable. For instance, Musca cestracea 

 of Linnc has been accepted for a very long period as a species 

 of Chilosia, but the slightest examination of Linne's original 

 description, which contains the words "scutello albido," would 

 have shown that liis species was no Chilosia, and then the 

 knowledge that the well-known Scandinavian Eristalis ajn- 

 formis exactly answered to Linne's M. oestracea, would have 

 been quite enough to identify the species without the need for 

 Haliday, in 1851, to call attention to Linne's original type. 

 The careless error arose because the Mid-European Dipterists 

 wanted to recognise M. oestracea in one of their own species, 

 while it happens to be a species confined to the extreme north. 

 Another point on which great improvement has occurred 

 is in the accumulation of longer series of specimens. It is 

 simply marvellous to me to notice the wonderfully good 

 descriptions made by Meigen from one, two, or three specimens 

 of a species, yet of course when one comes to an exceedingly 

 variable species one can see the trap into which the old 

 authors were sometimes led. We have not quite passed that 



