4i6 
ALBAN STEWART 
9. Smith, E. F. The Structure and Development of Crown Gall. U. S. Dept. 
Agr. Bur. PI. Ind. Bull. 255, pp. 1-60, pis. 1-109. 1912. 
10. Stewart, A. Notes on the Anatomy of Peridermium Galls I. Amer. Jour. Bot. 
(In press). 
11. Womle, P. Anatomische Untersuchung der durch Gymnosporangium-Arten 
hervorgerufenen Missbildungen. Forstl. Natiirw. Zeitsch. 3: 68-84, 129-172. 
1894. 
12. Reed, Howard S. and Crabill, G. E. The Cedar Rust Disease of Apples Caused 
by Gymnosporangium juniperi-virginianae Schw. Tech. Bull. 9, Virginia 
Agricultural Experiment Station. 19 15. 
EXPLANATION OF PLATES XV AND XVI 
Plate XV 
Gymnosporangium juniperi-virginianae on Juniperus virginiana 
Fig. I. Diagrammatic drawing of a longitudinal section through a very young 
gall and of the stem that bears it. C, central cylinder of stem. E, epidermis and 
hypodermis of leaf. K, cork layer. L, leaf trace bundles. R, resin cavity in leaf; 
X 42. 
Fig. 2. Diagrammatic drawing of a longitudinal section of a portion of a 
young juniper stem and an axillary bud. Bd, axillary bud. Other lettering same 
as in figure i ; X 42. 
Fig. 3. Diagrammatic drawing of a cross section of a stem near where it enters 
the base of the gall. B, tissue of secondary bark. K, cork layer; X 42. 
Fig. 4. Similar to fig. 3, but taken from a section deeper in the gall. B, modi- 
fied tissue of secondary bark. P, pith. S, accessory stem structure in the gall; 
X 42. 
Fig. 5. Similar to fig. 4, but taken from a section still deeper in the gall where 
the stem has become almost entirely disorganized. Lettering same as in fig. 4; 
X 42. 
Fig. 6. Diagrammatic drawing of a longitudinal section through the basal 
portion of an older gall and of the stem that bears it. B, modified tissue of secondary 
bark. C, central cylinder of main stem bearing gall. E, epidermis and hypodermis 
of leaf which has become involved in gall formation. L, leaf-trace bundle. P, 
pith of central cylinder inside gall. P, resin cavity in leaf; X 42. 
Fig. 7. Apparently normal branch growing from gall. B, more or less modi- 
fied tissue of secondary bark. K, cork layer surrounding gall. P, resin cavity in 
leaf; X 14. 
Plate XVI 
Gymnosporangium glohosum on Juniperus virginiana 
Fig. 8. Diagrammatic drawing of a cross section of the central cylinder near 
where it first enters the gall. B, modified tissue of secondary bark. C, portion of 
central cylinder of stem that bears the gall. Gp, gall parenchyma which entirely 
surrounds the parts figured; X 14. 
