101 
bacteria, and less commonly Rliizopus nigricans , which cause a rapid 
decay of the fruit. A number of affected plums were placed in a moist 
chamber and these were soon covered with a vigorous growth of 
Monilia, its mycelium spreading in all directions. Its growth subsided 
in a few weeks, when mycelial masses were formed. 
The plum fungus seems to differ chiefly from the one occurring on 
peaches in the shorter hyplise and somewhat smaller spores. Those on 
the peach are occasionally borne laterally. The more vigorous hyphae 
of the peach may be due to physiological causes. Mr. Ellis, to whom 
specimens were submitted, thinks it is a distinct species. 
Anthracnose of cur rants, (Gleeosporium ribis (Lib.) Mont, and Desm.).— 
Attention has been directed to this disease by several investigators.* 
It is very destructive, causing the leaves to become spotted on the 
upper surface, and to fall long before the proper time. Sometimes the 
leaves drop early in August. The spores come from small dark-brown 
specks. When ripe the epidermis breaks, allowing the spores to ooze 
out in tendrils. It is most commonly found on Ribes rubrum at Ames. 
Two other destructive diseases have also appeared on currants. One 
is caused by a species of Septoria. The spots are at first brown, later 
becoming pale on the upper and brown on the under surface. Each 
spot has a number of small conceptacles, which contain the slender 
spores. Another disease found on Ribes rubrum causes a similar spot¬ 
ting but does not contain conceptacles, the hyphse breaking through 
the epidermis and bearing the Cercospora spores. Both of these fungi 
cause the leaves to drop prematurely. The Septoria disease is the more 
destructive. 
CyUndrosporium padi , Karsten.—It has become practically impossible 
to grow good cherry seedlings on account of this fungus. Leaves begin 
to fall early in June, and where cherries are budded the young growth 
continually produces spores throughout the season. 
The cluster cup f ungus of gooseberries (JEcidium grossularice DC.) has 
been very destructive to cultivated gooseberries and a common culti¬ 
vated shrub, Ribes alpinum. It not only affects the leaves but causes 
the fruit to become greatly distorted and worthless. 
Black knot (Plowrightia morbosa ), although occurring abundantly on 
a large number of hosts of the genus Prunus , is especially destructive 
to Avild plums and cherries in this State (Prunus Americana , P. sero- 
tina , P. Virginiana ), frequently causing the death of the plant in a 
few years. It is not uncommon to find it on Prunus domestica , and 
within the last year it has been found on one of the Chinese apricots 
(Prunus Armeniaca) on the college grounds. The tree upon which the 
fungus was found has been subject to much pruning, and possibly in¬ 
fection has been brought about in this way. It is not improbable that 
^Dudley, Agric. Exper. Sta., Cornell Univ., Ithaca, Bull. 15, p. 196; Peck, 38tli 
and 43d Report N. Y. State Mus. Nat. Hist., p. 98, 6; Seymour, American Garden, 
Yol. xi. 
