Kinsey: Gall Wasp Genus Cynips 
63 
so the 93 species may be put into 28 groups and these in turn into 6 
subgenera which constitute two main groups, each of which is a closely 
compacted unit in its geographic distribution. 
Thus, while the genus cannot be based on any single diag- 
nostic character, the remarkable coordination of so many 
characters in so many species and the absence of anything 
approaching this combination of characters among any of the 
other members of the family testify to the phylogenetic unity 
of Cynips. There seems no reason for believing that such a 
body of coordinated characters could have arisen independ- 
ently in more than one time and place. In a single period, in 
a limited area, there must have existed a population from 
which all of the present-day species, with their varying grades 
of relationships, have developed. This history of the expan- 
sion of a single genetic stock into 93 distinct populations, by 
processes of mutation, isolation, and on occasion subsequent 
recombination into hybrid populations, is the story we have 
been unfolding in this study, and which we are now ready to 
fit into the geologic time and the geographic areas in which 
speciation probably proceeded in the genus. 
Cynips is in every respect a highly specialized genus of the 
oak-inhabiting tribe Cynipini of the family Cynipidae. The 
fossil record of the Cynipidae is meager and without signifi- 
cance except to prove that the family was in existence in the 
Oligocene and Miocene (Kinsey 1919; Cockerell 1921). There 
seems no reason for believing that the Cynipidae have ever 
been associated with any plants except the Angiospermae on 
which the family occurs today. The diversity of the present- 
day genera of the primitive gall makers of the Aulacini indi- 
cates that that tribe must have had a long history antecedent 
to the origin of the Cynipini. The family could not have 
originated before the rise of the flowering plants in the late 
Cretaceous, and it was probably much later before the 
Cynipini developed such specialized genera as Cynips and 
Disholcaspis. 
Our attempts to fathom the history of any of these higher 
genera must proceed on the assumption that all species of 
these groups have from the first been associated with oak, and 
our analysis of the cynipid history must do no violence to the 
known history of the sources and development of Quercus. 
To this end, the accompanying summary of the paleontological 
