ИИ 
d 
OBSERVATIONS ON THE CALIFORNIA VINE DISEASE 143 
“Tn the first stages of the disease the parasite develops more 
especially in the palisade tissue; it invades the cells of the lacu- 
nose tissue later, but is found only exceptionally in the epidermal 
cells. One observes in sections taken through recently affected 
tissue that healthy cells may contain starch in goodly amount, 
but that in the cells that are being invaded, it is much less abun- 
dant. The starch completely disappears with the spread of the 
parasite throughout the cell. . . . 
* Wherever the leaf blade is brown the tissues are infested, 
worst affected tissues, however, the infection is general; all the 
cells of the mesophyl are filled with the plasmodium. 
plasmodium presents the appearance of a sponge. At other times 
it lines the cell walls to a greater or less extent; this parietal 
plasmodium is more or less finely vacuolate and may be compared 
to fine lace-work. Protoplasmic strands sometimes join the 
various parts of the plasmodium and may even anastomose in a 
geneous, refringent, and oil-like; others that contain a large 
central or more or less excentric vacuole; lastly, others that are 
finely vacuolate and apparently composed of spongoid proto- 
plasmic matter," 
What is the cause of Brunissure? Viala and Sauvageau be- 
lieved that the vacuolate matter was a plasmodium, Plasmodio- 
bhora Vitis, and the globoids, homogeneous and granular matters, 
Products of decomposition. Debray considered that the globoids 
and the homogeneous (cereous) matter as well and the vacuolate, 
plasmodium-like masses were one and all phases in the develop- 
ment of an organism, Pseudocommis Vitis. Prunet as à result 
dui E 
ооо ы 
'Viala, P. Loc. cit., доз et seq. [ Translation.] 
