824 On the Diptera of the Amber-fauna. 
n 
some former period, as the impression left by such a comparison 
stock for both, it is to be sought among the Diptera of a former 
e 
Dipterous faunge are to be considered as branches of this : 
the necessary inference would be that at a former period Europe 
Al 
aentions. All those problems to which the study of the livi 
remained within the exclusive limits of Dipterology, partly ow 
ing to my conviction that the interest of truth is 
