OBSERVATIONS ON THE CALIFORNIA VINE DISEASE 125 
however, invariably changes in density, and not infrequently in 
character, on nearing the healthy tissues. 
In the palisade cells the deposit, as a rule, corresponds in 
density with that in the abutting epidermal cells (when there 
is a difference it will be in favor of the latter), but extends 
greatly beyond the outer limit of the matter in these cells. 
Homogeneity of the deposit is the rule, though it occurs now 
and then in granular form, the size of the granules varying from 
cell to cell, but not to any extent in the individual cell. The 
incrusting of the primordial utricle of the palisade cells is a 
striking and constant feature. The density of the incrustation 
decreases, as one passes from diseased to apparently healthy 
tissue. (PLATE 3, FIGURES 4, 6; PLATE 4, FIGURE 4.) 
In the lacunose tissue the incrusting of the lumen is not so 
regular or so marked as in the case of the palisade layer. The 
row of lacunose cells adjoining the palisade tissue is more free 
from it than the others, though there is no absolute constancy in 
this matter. These cells contain not infrequently, though scat- 
teringly, a few globules much smaller and constitutionally dif- 
ferent from those in the epidermal cells, as will be shown sub- 
sequently. In the remaining cells of the lacunose tissue the 
deposit is either homogeneous or granular, dense or thin, corre- 
sponding, in this respect, with the variations in the palisade layer. 
(PLATE 3, FIGURE 4; PLATE 4, FIGURES 3, 4, 5-) 
The chloroplasts are sometimes absent from the older portion 
of the diseased areas ` when present their, degeneration is marked, 
but, I should add, not unexceptionally, as sometimes palisade 
cells may be found filled with dense homogeneous matter in which 
chloroplasts, still containing starch, lie embedded. Degeneration, 
however, is the rule, but is more noticeable and has progressed 
further wherever the deposit in the cells is less dense; the chloro- 
plasts may then be observed as protean plasmodium-like masses, 
sometimes of considerable size, from aggregation of individuals. 
As one progresses towards the healthier tissues, and with the 
decrease in density of the deposit, the chloroplasts are generally 
more difficult to observe, their resorption having usually pro- 
gressed further. (PLATE 3, FIGURES 3, 4, б; PLATE 4, печ 
235) 
