Oscar John (St. Petersburg). 
Which palaearctic species belong to the genus Zethes 
Rambur? 
Оскаръ lou» (С.-Петербургъ). 
Kakie палеарктическе виды должны быть отнесены къ роду Zethes 
Rambur? 
More than once I have in my previous papers raised the ques- 
tion of generic affinity in different groups of Lepidoptera and every 
time I have tried to prove that the genital organs furnish us with the 
most valuable clues in this direction. If in these organs we have not 
yet, perhaps, found the ideal if there is any — criterion for phylo- 
genetic conclusions, we cannot but admit, that the comparative study of 
their structure brings us a good deal nearer the truth. But, however 
convinced we may be of the significance of the genital organs, we al- 
ways look for corroborating external features. But sometimes we come 
upon cases, when we are not able to find tangible, or rather, definite 
external characters to correspond with the internal. Let me remind the 
reader of the interesting case of Hydroecia nictitans, FH. lucens, Fl. pa- 
ludis and H. crinanensis, which, being so much alike and almost identical 
in external appearance, are distinctly divided into so many ,bonae species* 
by their male genital appendages. We are still under the influence of 
the methods of the past and are glad to find proofs for the intuitions 
of our predecessors, if they seem to be correct, but we are afraid to 
base new deductions on any new method. But there we are in the 
wrong, as we remain biassed by errors, which are due to the imper- 
fect methods of the elder authors, who were more arbitrary than strict 
in their conclusions and depended more on their intuition than on de- 
finite proofs. It is not a reproach to these authors when we say that 
their methods of investigation do not satisfy us. They have done their 
best at their time, but time has changed, new aspects have taken the 
place of the old ones; what seemed to be a truism yesterday is a 
doubt to-day, just as might happen to-morrow with the very founda- 
tions of to day’s scientific work. The principal rule is not to come to 
a standstill and, giving what is due to those who have worked before 
us, to go forward in our investigations of natural phenomena. 
The study of the genital organs of the Noctuidae lead me to one 
of those puzzling facts, when, the genital organs being quite different 
Revue Russe d’Entom. XII. 1912. Ne 1. 
