G8 
There is evidence that prune leaves are affected when the prune is 
grafted to almond stock. Nectarine leaves are also known to be attacked 
by Cercosporci circumscissa. Leaves from two-year-old nectarine grafts 
on diseased almonds grown on the place of Mr. Thurston were infested. 
GENERAL AND SPECIAL EFFECTS OF THE FUNGUS. 
On the almond tree the effects of this parasite appear on the new and 
old wood, the leaves, and the nut husks. The most important direct 
effects are on the leaves. The indirect action of the parasite is due to 
this injury of the foliage. When the foliage is seriously affected it falls 
prematurely, leaving the new wood partially ripened or immature. 
Where soil conditions will admit, a new terminal growth follows the 
defoliation. This may be compared to the renewal of peach foliage on 
trees denuded by the u curl-leaf 7 ’ fungus, Taphrina deformans , Tul., 
though the recovery and reclotliing of the almond is less complete. 
Where the soil conditions are unfavorable and moisture is deficient this 
secondary growth does not result. On the contrary the immature ter¬ 
minal wood becomes more or less dried and dead. The following sea¬ 
son many shoots may be broken with the thumb and finger. As the 
almond usually sheds its foliage early in the season and before the nuts 
have fallen, leaving the tree mostly denuded during the latter portion 
of the summer, any hastening of the defoliation subjects the immature 
wood to extremes of dryness and heat. In this respect there is a con¬ 
trast between the situation of the denuded almond tree and that of the 
peach tree defoliated through the action of the leaf rust, Pucciniapruni- 
spinoscc , P. In the latter case the leaves fall late in the season, after 
the extremes of drought and heat are moderated and the wood is less 
apt to become dry. The new foliage of the almond becomes infested 
like the spring foliage, but it is fresher and healthier than the latter at 
its fall. This arises largely from the recent pushing of the growth 
rather than through any diminution in the virulence of the disease. 
The trees and earth are covered by millions of spores capable of ger¬ 
minating within a few hours if placed under proper conditions of moist¬ 
ure. The humidity of spring is favorable to germination, while the 
spores are more numerous in the fall. Infested spots on the twigs are 
represented on Plate xi, Figs. 2 and 3. Fig. 2 is of natural size and 
represents new wood, while Fig. 3 is of old wood enlarged 2J diameters. 
In the former are shown nine points of infection in a little more than 2 
inches. The tissue here involved is sharply defined at the margin; 
and this is in general characteristic. The circular portion of the corti¬ 
cal tissue often falls out, leaving scars or pits in or through the bark of 
the twig. In other cases the dead tissue clings to the twig by the cen¬ 
ter of its inner surface, while the margin has warped outward, giving 
the piece the form of a watch crystal attached by its convex surface. 
A rather exceptional ease is shown in Fig. 3. This view is sufficiently 
