Kinsey : GoM Wasp Genus Cynips 
21 
preposterous Jordanon of botanical literature, may best be 
acquired by field experience with a group of related organisms. 
For illustration we may again utilize Cynips erinacei and 
some of its close relatives as they occur in the eastern portion 
of the United States. 
We have already described erinacei as a highly variable 
species occurring on the leaves of the white oak, Quercus alba, 
over a tremendous area chiefly in the northern Middle West. 
On almost all of the infested trees at any locality in this area 
one may find a mixture of smooth and spiny galls of every 
extreme and intermediate type. Often all types of galls are 
crowded onto a single leaf, but occasionally a particular tree 
will have a preponderance of one type, and on several occa- 
sions we have found isolated trees well covered, as far as we 
could discover, with galls of only a single extreme type. These 
peculiar colonies, however, have always been on isolated trees 
or groups of trees, and they would appear to represent 
Mendelian races in which homozygosity in regard to particular 
characters had been affected by the isolation of the colony. 
Subsequent examinations of insects from such galls have failed 
to indicate that these local populations are homozygous in 
regard to any of the other characters that might vary within 
the species, and such colonies are passed by the taxonomist as 
ephemeral entities not satisfying the species concept. 
If one will extend his collections in the first locality to a 
number of trees scattered over any appreciable distance — 
several hundred yards or a mile or two — he will leave the 
region with a sample that is as variable but as uniform as 
we have described it. If one travels to a second locality, five 
miles or fifty miles or a hundred and fifty miles from the first, 
the first collections may be duplicated. If one continues this 
procedure day after day, over the thousands of square miles 
which are the range of erinacei, one must become impressed 
with the fact that this is a population of inconceivably great 
numbers of individuals that are in certain aspects different 
and yet in an essential way similar over this tremendous 
territory. Of course, we can take only scant samples of the 
population, and we are reduced toi glancing at most of the 
trees with their thousands of galls which we have no time to 
gather; or we fall to wondering how many inconceivable 
millions of individuals of erinacei there are on all the trees 
