Aug. 26, 1918 
Susceptibility and Resistance to Citrus-Canker 
34i 
Chaetospermum glutinosa (Merrill) Swingle (Aegle glutinosa, Merrill). Tabog (CPB 
7799, seedlings), I, II. 
A small spiny tree, native to the Island of Luzon, P. I., of promise as a useful stock 
for Citrus. 
While several oily swellings have appeared on the young leaves, no definite canker 
spots have occurred. Isolations made from the suspicious spots yielded negative 
results. 
Subtribe Feroninae (Hardshell Fruits) 
Feronia Limonia (Corr.) Swingle (F. elephantum Corr.). Wood-apple (CPB 2763, seed¬ 
lings), I, II. 
A small spiny tree, native to India, Ceylon, and Indo-China. 
The leaves have remained free from canker spots. 
Feroniella lucida Swingle. Kavista Batu (CPB 7882, seedlings), I, II 
A small spiny tree, native to Java, somewhat resembling Feronia Limonia . 
No spots have appeared on the leaves. 
Subtribe Lavanginae 
Hesperethusa crenulata Roem. Naibel. (CPB 2759, seedling), II. 
A slender tree native to the hills of India, Burma, and Indo-China. 
No canker spots have developed on any of the leaves, although small spots caused 
by a fungus have been numerous. 
Triphasia trifolia P. Wilson. Lime berry (CPB 2689A and 7780, seedlings), I, II, 
and II. . 
A small tree widely cultivated in tropical and subtropical regions as an ornamental. 
These plants (10 to 18 inches) did not thrive well in the inoculation cases, and 
the lower leaves turned yellow and fell rapidly. However, new growth was pro¬ 
duced quickly, so that young leaves were present at all times. No spots of any 
nature have developed on the leaves. 
Severinia buxifolia Ten. (CPB 2760, cuttings), I, II. 
\ dwarf tree native to South China, introduced into Europe and recently into 
America. 
The plants (8 to 12 inches), like Triphasia trifolia, did not thrive well in the cashes, 
and defoliation was severe. However, new growth was present, and in good condi¬ 
tion for infection. No spots of any kind have appeared on the foliage. 
Subtribe Citrinae 
nonedible fruits having sessile pulp vesicles with broad bases 1 
Citropsis Schweinfurthii Swingle and M. Kellerman. African cherry orange (CPB 
11260, seedling), II. 
A small spiny tree native to Central Africa. 
No spots of any kind have appeared on the leaves. 
Atalantia citrioides Pierre. (CPB 7534, cuttings), I, II (2 plants). 
A small spiny tree native to Indo-China. 
These plants (6 to 10 inches) did not thrive in the greenhouse, the leaves defoli¬ 
ated rapidly, and in January all but one plant was discarded. However, new growth 
took place during the experiments, so that infection was possible. No canker spots 
appeared. 
1 In a recent conference with Mr. Swingle he stated that the subtribe Citrinae might well be split up 
into two groups to include plants having (a) nonedible fruits having sessile pulp vesicles with broad bases, 
and (6) edible fruits with stalked pulp vesicles. 
