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J. L. WEIMER 
Fig. 2. Mature gall of G. Juniperi-virginianae developed from the upper 
surface of the leaf and producing one telial horn. 
Fig. 3. Three mature galls of G. Juniperi virginianae with telial horns partly 
gelatinized. These galls have evidently developed from the upper side of the 
leaves upon which they occur. 
Fig, 4. Longitudinal section of stem and leaves of young cedar twig showing 
the relation of the gall {g) to the leaf (/) which bears it and to the leaf on the opposite 
side of the stem. 
Plate XIII 
Fig. I. Young gall (g) forming on the leaf (/) at a considerable distance 
from the stem {s). The vascular tissue in the young gall is very abundant and arises 
from the leaf-trace bundle (/)• 
Fig. 2. A young gall borne near the tip of the leaf showing the vascular 
development as in Fig. i. The letters correspond to those in Fig. i. The connection 
of the vascular tissue is more readily visible. 
Fig. 3. A transverse section of a stem {s) with two opposite leaves {I and /'). 
A gall (g) has developed from the side of leaf / and vascular strands {v) are derived 
from the enlarged leaf-trace bundle at /. 
Plate XIV 
Fig. I. Section through a leaf (/) with a basal gall, the section taken as shown 
in diagram and transverse to the leaf trace. The vascular bundle {v) is considerably 
enlarged. Only one bundle is present, supplying both leaf and gall. This precludes 
the possibility of a separate origin of the vascular system of the gall, i. e., of the axial 
nature of the latter. (See text figure i.) 
Fig. 2. Section of the same leaf (/) as shown in Fig. i but taken farther from 
the stem {s). The vascular bundle has broken into three distinct segments. 
Fig. 3. Section from the same leaf as in Figs, i and 2 but taken still farther 
from the stem. Here the vascular tissue has become much diffused. 
Fig. 4. Transverse section of a medium-sized gall (g) and the stem which bears 
it (.r). The leaf on the opposite side of the stem is shown at /. The vascular tissue of 
the gall originates as one large strand at a which finally breaks up into a fan-like 
system of bundles. How this takes place is made clear by a careful study of Figs. 
I, 2, and 3. 
Plate XV 
Fig. i. Longitudinal section of young stem {s) showing terminal bud ih), 
young gall (g) and leaves (/). The bud {h) has identically the same appearance as 
the young gall shown by Stewart (1915) in Fig. i of his paper. There is no mycelium 
in this bud while mycelium is abundant in the gall beside it. 
Fig. 2. Telial horns of G. glohosum issuing directly from the leaf. 
Figs. 3 and 4. Young galls of G. glohosum originating from leaves, the tips 
of which are apparent at the top of the galls. The white appearance of the upper 
portion of the galls is due to fragments of the leaf tissue. 
Figs. 5 and 6. Mature galls showing the remains of the leaves from which 
they originated. The galls shown in Fig. 5 have fruited more than once. 
Fig. 7. A transverse section of a leaf which was slightly discolored and very 
slightly swollen at the base. The leaf is permeated with mycelium throughout nearly 
