GALLS PRODUCED BY TWO CEDAR RUST FUNGI 
245 
affected by the gall and it soon becomes developed to such an abnormal 
extent that its identity i'^ nearly or quite lost. Reed and Crabill (191 5) 
give a good diagrammatic drawing of the bundle of a young gall 
originating near the stem. Stewart (1915) thinks that had Reed and 
Crabill made transverse instead of longitudinal sections of this infected 
leaf they would have found two bundles entering the gall rather than 
one. Such sections of numerous galls have been made by the writer 
and in no case has more than the one abnormally large bundle been 
found. In Plate XIV, Figures 1,2, and 3 are shown sections from a 
series cut from an infected leaf, the gall being formed near the axil. 
A section taken a little way above the junction of the leaf and stem is 
represented in Figure i (line a-h, text figure i). Here it is evident that 
the vascular bundle has been affected since 
it has more than doubled in size. A section 
taken farther from the stem is illustrated in 
Figure 2 (line c-d, text figure i). This 
shows the bundle split into three parts by 
the intercalary formation of large cells 
filled with resin. These segments of the 
vascular system later branch out and be- 
come diffused throughout the gall (Fig. 3) 
(line e-f, text figure i). A photograph of 
, a stage somewhat comparable to Stewart's 
text figure is shown in Plate XIV, Figure 
4. The central cylinder of the stem is 
shown at a and passing off from this is the 
greatly enlarged and modified leaf trace 
bundle breaking up and passing out in all 
directions in the gall. In Plate XIII, Fig- 
ure 3, is shown a transverse section of 
the stem at 5 with two leaves at / and 
From one side of leaf / a gall (g) 
is being produced. The vascular system of leaf / is much enlarged 
and from it strands of vascular tissue {v) extend into the gall {g). 
These figures check the opinion of Reed and Craybill concerning the 
single bundle supply. In cases where the gall occurs near the leaf 
base the increase in vascular tissue occasioned by its presence enlarges 
the leaf trace even through the cortex. At the base of the gall its 
vascular tissue frequently takes the form of an irregular hollow cylinder 
Text-fig. i. Diagramma- 
tic drawing of a portion of a 
cedar twig with two leaves 
attached. Lines a-h, c-d, and 
e-f show the approximate po- 
sitions from which the sec- 
tions illustrated in Plate XIV, 
Figs. I, 2 and 3 respectively, 
were taken. 5 — stem, g — gall 
and / — leaf. 
