AN ANATOMICAL STUDY OF GYMNOSPORANGIUM GALLS 413 
figs. 13, 14, and 15. A portion of the woody cylinder (fig. 9), pushes 
outward in the manner shown in fig. 13. This projection becomes 
larger and somewhat expanded at the apex while it contracts at the 
base (fig. 14). Strands of tracheids, surrounding broad, ray-like 
masses of parenchyma, often fill up the constricted portion as is shown 
in the figure. After a time the projection becomes separated from 
the central cylinder, or nearly so (fig. 15), after which it assumes the 
character of the main woody cylinder from which it arose, except 
that it is smaller in size. 
I have been unable to determine the cause of these accessory stems, 
but, arising as the gall does from a transformed axillary bud, it is 
not unreasonable to suppose that latent properties for bud formation, 
inherent in it, are stimulated to activity through the action of the 
fungus. 
A longitudinal section through this type of gall is shown in fig. 10. 
The section figured was made at right angles to the ones shown in 
figs. 8 and 9. A portion of the stem which bears the gall is shown at 
c. Strands of tracheids go off from this on the right and left sides 
of the figure. This is surrounded by gall parenchyma (gp) which is 
surrounded on the outside by cork (k) . 
In the second type to be considered, the woody cylinder preserves 
more of its normal structure at the point of entrance into the gall, 
and is more like the galls of G. juniperi-virginianae in this respect 
than in the type just described. The woody cylinder is not greatly 
altered at first, but there is a considerable production of parenchyma 
at the expense of the tracheids. Many of the parenchyma cells have 
the form of tracheids when seen in cross section, but the walls are 
unlignified and protoplasm is present in them. Broad rays are formed 
which cut the cylinder into wedge-like masses similar to the one 
shown in fig. 12. Bast fibers occur but seldom in the secondary bark 
tissue, similar in this respect to the first of the type of glohosum gall 
described. 
A short distance beyond the point of entrance of the stem into 
the gall, the pith begins to enlarge and the rays broaden, thus pushing 
the xylem wedges farther apart. This process is attended with more 
or less displacement of tracheids in sectors of the cylinder. The 
enlargement of the pith and other abnormalities continue, until 
deep in the gall the woody cylinder assumes a form very similar to 
that shown in fig. 9, where most of the groups of tracheids extend in 
