Kinsey: The Genus Neuroterus 
133 
Neuroterus, before Adler discovered the relations of the two. 
It is hard to understand how the generational differences 
in these instances could ever have been considered of generic 
rank, and it is not a fair account of Neuroterus heterogeny 
which is described as alternation between two genera. The 
following translations of Adler’s work are so well known 
that they need criticism in this place. Following his account 
of the alternating forms of the four insects listed above, he 
says (translating) : 
The forms of N euroterus and Spatheg.aster, which I have just de- 
scribed, have heretofore been considered different genera, altho they 
are only two generations of the same insect. One was indeed quite war- 
ranted in such a treatment, since there are well marked differences be- 
tween the two generations. A comparison of the galls will show that 
they cannot be confused, for the differences between the galls of the two 
generations of the same insect are rather greater than between two 
different species, such as lenticulaHs and numismatis. 
Right here it should be noted that Adler was not compar- 
ing distinct species, but varieties of one species, as I have 
already suggested. A fair statement would be that the differ- 
ences between the galls of the varieties of a species are not 
as great as between the galls of some alternate generations. 
This amounts to something less than Adler’s generally ac- 
cepted interpretation. It is a very common thing to find 
slight variation in the galls of varieties of a single species, 
but a rare thing (except among very primitive Cynipidae) 
to find similar galls in different species. The alternating 
galls of Spatheg^aster forms do differ in details of form, but 
not in fundamental plan or location. Translating further: 
We shall consider further on the importance of the sexual distinc- 
tions of the insects, bisexual in one generation, agamic in the other; 
parthenogenetic reproduction, of constant occurrence in Neurot&rus, is 
now so well established that one does not need additional proofs. 
If one compares the wasps of the two generations of the species 
described herein, they exhibit, externally, for the most part only very 
slight differences. The differences of coloration are insignificant and are 
restricted largely to slight variations in the colors of the legs; the sizes 
are not greatly different; the forms and sculptures of the insects are in 
general uniform. Nevertheless it is not very difficult to distinguish the 
two generations. If the two forms are placed side by side they cannot 
be confused. Indeed, the structures are quite different. Neuroterus is 
more compressed, the abdomen more especially developed, the wings 
generally shorter than and the antenna about two-thirds the length of 
