146 Ture Microscope. 
CYNIPS QUERCUS-CORNIGERA AND HER GALLS. 
DR. ALFRED C. STOKES. 
Rees of our forest trees are so frequently attacked by the 
gall-flies as the oak. The punctures, the injected poison, 
the presence of the minute eggs, one or all of these causes com- 
pel the tree to bear the deformities on its limbs, twigs, leaves, 
buds, and even on its flowers and roots, while the excresences 
themselves are as diverse in size, form, color, consistence, and 
degree of roughness as in position. A peculiar deformation is 
the one following the punctures of the Cynips quereus-cornigera, 
Osten Sacken. 
A tree near my home is as heavily loaded with these galls 
as any cherry tree with cherriesin June. They are olive green 
in color, remarkably hard,and vary from the size of a hazel-nut 
to that of a walnut, becoming somewhat spherical by growth 
around the twig. Their surface is studded with brown spines 
projecting one-fourth of an inch or more, and arranged in irreg- 
ular longitudinal rows (Fig. 1), while they consist internally of 
a whitish tissue, spongy but dense, in which are embedded the 
prolonged bodies roughening the surface. The latter are woody 
externally, usually extending to the centre of the growth being 
closely embraced by the gall tissue, but separable from it, and 
when mature tapering from a rounded base to a sharp often 
curved apex. Each is entirely distinct from every other, and 
each is separated within by a transverse woody partition into two 
unequal cells, the lower and smaller containing the plump little 
