AN ANATOMICAL STUDY OF GYMNOSPORANGIUM GALLS 405 
arisen from the infection of a terminal bud such as has been suggested 
by Wornle. They were always distinctly axillary in position although 
on the same tree with them there were older galls which were appar- 
ently terminal. According to Sanford (8), the branch is pushed to 
one side during the development of the gall. If this be true the 
terminal position of many of the older galls is probably more apparent 
than real. 
The leaf, from the axil of which the gall arises, is pushed outward 
to some extent so that a small shelf is formed on which the gall rests. 
Apparently the fungus has not entered the stem at this stage as no 
abnormalities appear beyond a slight production of cork just above 
the gall (fig. i). In the stage figured, the gall consists entirely of 
Text fig. i. Semi-diagrammatic drawing of a cross section of a young gall 
of Gymnosporangium juniperi-virginianae and of the stem that bears it. Normal 
leaf shown below with resin cavity (r). Immediately above this is the central 
cylinder of the stem, and above this the central cylinder in the gall with its branches. 
E, epidermis and hypodermis of leaf; K, cork layer surrounding gall; R' , resin cavity 
in gall; X 42. 
