NOTES ON THE ANATOMY OF THE PUNCTATUS GALL 
Alban Stewart 
Our knowledge of the anatomy of Cynipid galls is based largely 
upon the investigations of Beyerinck, Hieronymus, Kiistenmacher, 
Kiister, Lacaze-Duthiers, Prillieux, and Weidel, but as the publica- 
tions of these various authors have to do mainly with other than 
American galls, our knowledge of the anatomy of these remains meager 
for the most part. 
During the summer of 191 3 I was fortunate enough to discover a 
tree of the black oak, Quercus velutina Lam., in the western part of the 
state of Missouri, the smaller stems and branches of which were 
covered in places with galls caused by Andricus punctatus Bass. As 
there were galls on this tree in different stages of development, I 
collected a series and preserved them for further study. The galls 
caused by this insect are rather striking in appearance as they form 
knot-like swellings on the branches, which sometimes attain a diam- 
eter of five or more centimeters. The most of them, however, are 
smaller than this. They may occur singly, or two or more of them 
may be closely associated, one above the other on the same branch, 
which may become joined together by subsequent growth so as to 
appear as one gall. When they occur close together on the same 
branch, in the earlier stages of their development, the smaller galls 
are usually located towards the distal end. 
The larger galls are roughened on the outside and are covered with 
small openings about i mm. in diameter, each of which leads into an 
empty larval chamber (fig. 10). Each opening is usually surrounded 
by a circular area, about 3 mm. in diameter, in which the surface of 
the bark is smoother and lighter in color than elsewhere. The openings 
persist for quite a while after the chambers are vacated, but they may 
ultimately become more or less obliterated by the subsequent growth 
of the gall. The larval chambers extend inward from the openings 
in a direction usually more or less perpendicular to the outer surface 
(fig. 2), so that cross sections of older galls will generally show various 
views of different chambers in the same section. 
It is very evident that these galls may continue to grow for several 
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