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Indiana University Studies 
eties of a single species. This is in accord with all known 
cases in the genus. 
None of these assumptions will appear radical, nor do they 
introduce anything new. The only advance comes in con- 
sciously formulating and deliberately applying these principles. 
These will need some modification if they are to be extended 
to other genera, and in the higher Cynipidse it will be much 
harder to predict beyond our direct knowledge. We are for- 
tunate in dealing now with such a primitive group as 
N euroterus. 
The more primitive condition would involve a succession 
of generations which were all bisexual. The occurrence of 
two successively bisexual generations in a year is not yet 
proved in Cynipidse, but there is a suggestion that it may 
exist in N euroterus vesicula where both a winter variety and 
a spring variety are known to be bisexual. There is no proof 
here, but a suggestion worth investigating. Most of the 
species with known life histories have a bisexual spring gen- 
eration alternating with an agamic, over-wintering genera- 
tion; the galls are always very similar, and the insects very 
largely identical. The dates of emergence of the two genera- 
tions are much earlier for some species than for others. The 
males in the bisexual forms irregularis and decipiens are much 
reduced in numbers. Dr. Patterson has made the interesting 
discovery that the agamic generations of N. contortus and 
N. rileyi mutatus produce a few males, these appearing to be 
fimctionless. Here is a step which is intermediate between 
the more primitive and the more common life histories, and 
the details of Dr. Patterson’s observations will have very great 
interest when they are published at a later date. Finally there 
is a suggestion, not yet proved, that in saltatorius (and 
urdhilicatus?) we have two agamic generations coming in suc- 
cession in a year. This would constitute the most highly 
evolved mode of reproduction, and one as yet proved for 
only the five species which Adler worked with. 
Altho N euroterus is primitive in several respects, there 
appears to be some specialization in reproduction, with such 
wide variation in the group that we may yet find that we have 
all steps in the evolutionary story within this single genus. 
