184 
Indiana University Studies 
small, inconspicuously green in color, and so ephemeral that 
the chances of their collection are much reduced. They are 
bud galls that appear with the bursting of the leaf buds the 
first thing in the spring; they reach full size within a few 
days, and are then so loosely attached to the young, devel- 
oping stems that they fall to the ground in a heavy wind or 
at the slightest touch. The larval insects reach full size rap- 
idly and, transforming into adults, emerge within perhaps 
three weeks after the galls first appear. Emergence thus 
varies with the season, latitude, and altitude, the limits of 
our scant records being March 23 further south (at Three 
Rivers for form vibes) to May 13 further north (at Kelsey- 
ville for form atrata ) . Most of the emergence is probably in 
April. The males are not rare in our collections and they are 
probably produced in equal abundance with the females. Ovi- 
position has not been observed, but it must be in the veins 
of the then young but unfolded leaves, for the agamic galls 
appear within a month and a half to two months of that time. 
The bisexual galls shrivel very greatly when collected and 
dried, and decay very rapidly when moist, the latter being 
the explanation of our complete failure to find them except in 
the short season before the maturity of the insect. 
The young galls of the agamic forms first appear, at least 
north of the Sierra Madre, early in the summer; the larvae 
are mature within a couple of months, and the adults mature 
at various times from then on, emergence occurring in De- 
cember or January. It should be noted that in mid-winter, 
in most of the areas involved, freezing temperatures are rare 
(varieties echinus and douglasii ) , while the colder days and 
snow storms of other parts of the region are intermingled with 
warm days when emerging insects might easily become active. 
The insects and the galls of the bisexual and agamic forms 
here described have not hitherto been recognized as successive 
generations, for they are superficially quite distinct. They 
are not yet connected by the experimental data to which our 
conclusions must always be subject; but a closer examination 
shows so many points of similarity and so much confirmatory 
host, distribution, and life history data that we may be justi- 
fied in our present interpretation. 
In the first place, the bisexual insects clearly belong to the 
genus Cynips and to the subgenus Antron. 
