OBSERVATIONS ON THE CALIFORNIA VINE DISEASE 141 
tissues outlining the main venation of the leaf. All colors vary 
according to the time since the first alteration took place. The 
petiole is not involved at once in any evident change, but later 
the leaf is cut off. A second variety of grape had leaves altered 
in a somewhat similar manner to those of the dark varieties de- 
scribed, but the bright colors did not prevail. There was little 
to be seen of a third color on these leaves. The alteration 
is almost directly from the normal green to a dull muddy brown, 
as if the base colors were yellow and black. The dead tissue 
occurs first at the margin, and in spots and stripes between 
the main veins, rarely if ever touching a large vein. Between 
this dead tissue and the green next the veins is sometimes a 
slight transitional shade of yellow, which is nearly wanting in 
many cases, the brown being directly joined to the green on 
either side of the main veins. Where the intermediate yellow 
line is wanting, the appearance of the leaf is very striking, 
and differs in color from any diseased varieties noticed in 
California. The pattern of the markings is, however, the same. 
The difference observable is a varietal one. The leaves of a 
variety of white grape were altered in the manner described for 
the Muscat of Alexandria in California. In the early stages the 
changes of the leaf are foreshadowed in faint yellowish spots im 
the parenchyma, which become more pronounced as the trouble 
advances. At this time the leaf may have a yellow speckled 
appearance. The spots are yet somewhat cloud-like and illy de- 
fined, and are rarely located upon a vein. As the discoloration 
becomes more marked these cloud-like spots are better defined at 
their margin and more and more of the parenchyma of the leaf 
between the veins becomes involved. As the light yellow spots 
enlarge the parenchyma at their center turns reddish brown and 
dies. Later there is a brown central stripe between the veins 
and at the margin of the leaf, and bordering this dead tissue 15 4 
line of half-dead yellow tissue lying next the green bordering 
the veins. All these markings are very distinct and well defined 
in the later stages of the trouble. As the death of the tissue 
between the veins progresses it gives to the green bands at the 
veins the symmetrical appearance seen on the Muscat leaf in 
California," 
Rougeot has been ascribed to the same cause as Folletage. 
Sun-scald.— This malady is described as follows by Viala: 
somewhat depressed 
mes affected periph- 
“ ^ А 
Sun-scald appears as irregular intervenar, 
feuille-morte maculations. Leaves are зотей 
* Pierce, М. В. Loc. cit., 186. 
