SCIENTIFIC NOTES, 
161 
since I have demonstrated the near relation between the two faunae 
exhibited by Noctuid^ of the old and new world. The characters 
drawn from the male genitalia must be ranked with those from the 
antennae. They are sexual or secondary characters. On this account 
to use them as the sole basis for generic separation is hardly necessary. 
The genitalia in the Noctuid/e are found to differ markedly in other- 
wise very closely related species. In other species, easily distinguish- 
able, they are practically of the same pattern. Undoubtedly we must 
know and study all the parts of an insect, but no single character will 
enable us to classify an order. It will be found impracticable to classify 
the moths by their tails, as by their wings alone or chi-efly, as attempted 
by Herrich-Schaffer. /\mong the representative species this chan'j;e in 
the structure of the genitalic appendages is instructive and indicative of 
their morphological value. The European A<^rotis augur is a well- 
marked and tolerably isolated species, presenting peculiarities in shape, 
size, colour and pattern. In all these respects the American Agrotis 
haruspica is nearly its exact counterpart. As the basis of separation of 
the two, the immature stages not having been used, we have a tendency 
to obsolescence of certain markings and perhaps a hardly perceptible 
change in the exact shade and average size in haruspica. Now the 
genitalia are shown to differ in pattern as well. From this fact we must 
logically conclude that the genitalia are more easily impressed 
and changed by environment than colour, size, pattern or other 
structure. Consequently the genitalia are subject to variation, and 
-the question rather comes up, are the characters drawn from the male 
genitalia of specific value? The true ground for considering the two 
species distinct is that they do not interbreed and produce each other, 
and that so far the American examples may be picked out by experts. 
When these conditions can no longer be fulfilled there would be no 
ground for retaining a different name. The mere fact of their inhabit- 
ing differing continents is not sufficient, they must breed true to type 
and not produce each other. Then we can be sure we have to do 
with separate cycles of existence, and we can catalogue the fact. As 
the genitalia are concealed, their structure is not so apparent, and it is 
clear that repeated observations are necessary to verify the statements 
drawn from solitary dissections. But, granting what has been published 
as substantially reliable, there yet remains the test of breeding 
to be applied to the genitalic species. We have an instance in 
the genitalic species of JVisionades. These butterflies have not been 
bred to ascertain if they remain true in their genitalic peculi- 
arities, if one genitalic type does not produce the other, if the 
caterpillars show no differences. Until all the matters are cleared up 
we can arrive at no final conclusion as to the value of genitalic cha- 
racters, as to which single observations must be checked by repeated 
experiments. Writers on the subject have apparently proceeded on the 
basis that the male genitalia are formed, not by deposits of chitine but 
of cast iron, moulded so as to fit and give at last a stable and firm 
reality to our artificial system of classification. Vain expectations. 
The characters on which we are obliged to found all our categories, 
are one in quality and only differ in quantity ; what is generic is 
specific also, and what is specific is varietal.” — Canadian Entomologist. 
July, iSpr. 
