414 
ALBAN STEWART 
various directions. A few of them still remain in their normal position 
and appear as the xylem wedges, mentioned several times before in 
this article. Sooner or later the various groups of tracheids diffuse 
outward into the gall and all semblance of a central stem structure is 
lost. 
Gnarl-like complexes of tracheids and parenchyma cells occur in 
both of the types of globosum galls described. The one shown in 
fig. II consists of a mass of cells wound around a parenchyma center 
and is not dissimilar to the ''Knaueln" described by Maule (7) from 
traumatic wood. Cells which are transitional between tracheids and 
parenchyma are shown in this figure. One end of such a cell usually 
has a lignified wall in which there are scalariform pits, while at the 
other end the wall is of cellulose and a protoplasmic content is present. 
Transitional cells of this nature have been reported in several other 
kinds of pathological plant tissue. Maule (7) has found them in the 
traumatic wood of Abies cephalonica ; Smith (9) has described and 
figured somewhat similar cells in the tumor strand of crown gall on the 
tobacco stem; and the writer has found such cells to be present in 
the galls of Peridermium cerebrum on Pinus Banksiana (see Stewart 
(10)). Such cells have probably been reported in still other kinds of 
abnormal plant tissue. They seem to have quite a wide distribution. 
Methods 
In preparing material for study, the galls were embedded in 
celloidin as there was too much lignified tissue present to get good 
section when embedded in parafin. The sections were usually mounted 
in series and stained with safranin. Either Delafield's hematoxyHn or 
"licht Griin" was used as a counter stain. The drawings were 
made with a Spencer Delineascope and are diagrammatic for the 
most part. In order to cover wide enough field to show all of the 
structures desired, a low magnification was necessary. Great detail 
was impossible under such circumstances. 
Summary 
1. Gymno sporangium juniperi-virginianae and G. globosum cause 
the formation of large galls on the younger branches of Juniperus 
virginiana. 
2. The galls arise from the axils of the leaves and are evidently 
transformed axillary buds. 
