THE ENTOMOLOGIST. 249 
saucer-shaped and situated beneath the larger, and between 
this and the twig to which it is attached; the spherical body 
represents the carpel of the acorn, or the acorn proper, and 
the saacer-shaped cushion, on which it rests, represents the 
cupule or cup, or calyx. Having ventured to call the entire 
gall a pseudo-balanus, or false acorn, so will I call the spherical 
portion the “ pseudo-carpel,” and the cushion the “ pseudo- 
calyx.” On carefully examining the pseudo-carpel—projecting 
from it exacly opposite the point of attachment, and there- 
fore on its summit—will be found a small pointed process, 
which represents the persistent stigma of the acorn; and the 
exterior covering of the pseudo-carpel—tough, leathery, and 
smooth—represents the pericarp of the acorn. I fail to 
discover, either on the real or false acorn, the markings so 
clearly expressed in Dr. Mayr’s figure. The resemblance or 
mimicry of the true cupule by the false one is not very 
evident; the relative magnitude of acorn and cup are very 
different, but the composition is the same. If I understand 
that of the true acorn correctly, it is made up of a number of 
involucral scales or bracts, soldered, anchylosed, and com- 
pressed together into acupular form; and this I believe to be 
equally the explanation of the mimetic cupule. As in the 
true acorn, a vertical section will bisect the stigma, the 
carpel, and the cupule, showing that there is the same method 
in the arrangement of the parts of the false and true acorns. 
Until a year or more has elapsed I can find no tendency to 
dehiscence at the base of the pseudo-carpel, but during the 
second year I have repeatedly observed this dehiscence, the 
pseudo-carpel falling to the ground like an acorn, and 
exhibiting a cicatrix at its base, while the cushion, cuptle or 
pseudo-calyx, retains its adhesion to the twig. This is also 
the case with the Aleppo galls, Cynips galle-tinctoria, which 
dehisce and fall in numbers every autumn. 
This is emphatically the species on which the most careful 
observations have been made, with a view to settle the 
doubtful point, whether or not the species is continued from 
‘year to year by a succession of females only, or whether 
males do exist in alternate generations or in some undis- 
covered form. The latter seems the more reasonable con- 
jecture, and I think was first promulgated by the late Mr. 
Walsh, at p. 320: of the second volume of the ‘ American 
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