GOLDSTEIN: PLANTS AFFECTED WITH Mosaic DISEASE 265 
preparations of tissue kept in a moist chamber for several davs. 
Their content, however, becomes very granular, and no move- 
ments of the body or its contents were observable after the second 
day. 
The X bodies as I have noted often exhibit distinct but 
-sluggish amoeboid movements. They also are bounded by a 
definite plasma membrane as is clearly shown when the more 
active X bodies thrust out short rounded pseudopods. The 
presence of this membrane can also be demonstrated when acids 
or drops of fixing solutions are added to the water under the cover 
slip. The content of the body then contracts thus showing that 
it is separated from the cell sap by a definite limiting layer. The 
contents of the contracted X body also appears more coarsely 
granular and distinctly vacuolated. 
In figure 5, the nucleus lies suspended in the cell vacuole. 
The body here is granular in structure, and showed conspicuously 
a sort of vibratory motion, and perhaps a circulation of its granu- 
lar content. This body continually changed its form by putting 
out slight bulbous projections on all its surfaces which were 
withdrawn again after several seconds, while other projections 
arose in other parts. It continually showed changes of position, 
moving up over the nucleus, or across the striated body, and 
then back again to the position shown in the drawing. These 
motions were not easily to be associated with the streaming 
movements of the cytoplasm. The X body did not as long as 
the cell was observed, during a period of several hours, move 
away from the vicinity of the nucleus and the striated body. 
Such amoeboid X bodies have also been observed to move 
through the cell. The amoeboid processes are put out in the 
direction of the movement, and these often show a clear hyaline 
area at their blunt extremities. I am not certain, however, that 
‘the entire movement of the X body is due to the thrusting out of 
these projections though the entire body appears to move for- 
ward at the same time that the projection is put out. When the 
‘ body turns after moving forward in a certain direction, it 
elongates, or becomes less rounded, or oval, and this elongation 
is in the direction of the turning movement. The body may now 
appear pear shaped. The upper narrower region now swings 
around toward the direction in which the body will soon begin to 
move. 
