OBSERVATIONS ON THE CALIFORNIA VINE DISEASE 153 
ConcLuston.—The facts gathered during the course of this 
paper point to the conclusion that the California vine disease is 
due to some weakness in the functions of absorption and translo- 
cation of water becoming manifest when conditions favoring 
transpiration are marked. To say that the disease is due to a 
rupture of equilibrium between absorption and transpiration does 
not conflict with any recorded observations. This is true whether 
one considers the disease from the point of view of the effect of 
external agencies upon its general development, or from the point 
of view of its development upon individual vines, or from the 
point of view of its symptomatology, anatomy, and relationships. 
CORNELL UNIVERSITY, 
ITHACA, NEw YORK. 
Explanation of plates 1-5 
PLATE 1 
1,2, 3, 4. Young diseased leaves of Vitis vinifera, var. Missi 
eaf of V. vinifera, var. Muscat of Alexandria, showing ыы stria- 
tions and death of tissues at edge of blade. 
PLATE 2 
Leaves showing various stages of disease. 
1,2, 3." V. vinifera, var. Mission. 
4 5. Г. vinifera, var. Berger. 
PLATE 3 
1, 2, 3, 4, 6. Sections through palisade tissue of leaves in various stages of 
disease, 
5. Cross-section of a small fibro-vascular bundle. 
PLATE 4 
. Cross-section of part of а fibro-vascular bundle of a main vein showing 
development of thylloses in the vessels. 4 
Section of healthy leaf showing normal appearance of chloroplasts e 
3,4,5. Sections through palisade tissue showing various stages of diseas 
PLATE 5 
1, 2, 3. Cross-sections of diseased cane nicis 
B, phloem; C, cortex; F, bast fiber WE М, medulla; P, регісу 
fibers; К, Фейн rays; 5, suber; X, xylem 
