W. @. Farlow—Disease of Olive and Orange Trees. 87 
Art. VI.—On a Disease of Olive and Orange Trees, oceurri: 
in California in the Spring and Summer of 1875; by W. G. 
Fartow, Assistant Professor of Botany in Harvard Univer- 
sity.* With Plate III. 
DurinG the past summer, numerous complaints have come 
from southern Galifornia of a fungus which had attacked the 
olive and orange trees, and which was causing a considerable 
loss of those two crops. Our attention was first called to the 
subject by Dr. H. W. Harkness, who, in a letter from San Fran- 
cisco dated May 11, sent a specimen of the fungus on an orange- 
leaf from southern California. Of the extent of the ravages of 
lemon and orange trees. A small fungus appears on the leaves, 
twigs, and branches, at first visible only with a microscope, and 
of a green color. As it increases in size it turns brown, and 
then black. The olive is so exhausted that it is unable to fruit. 
The orange and lemon stand it better, but their fruit is so infe- 
rior as to be practically worthless.” On the day of the receipt 
of Dr. Thurber’s letter, another was received from Professor 
Dana, also enclosing specimens from Santa Barbara. 
From the general tenor of letters from California, it is evident 
that, if this is not the first year of the appearance of the disease, 
it is, at least, the first in which it has attracted general atten- 
* Copied from the Bulletin of the Bussy Institution. 
+ We are in receipt of a letter eas ee Cleveland, dated early in es rope 
in which he sends specimens of the fungus on orange-leaves, which, 
at that ti at San Diego. 
