Cak n e — B roicn Hot of Cit rus. 
23 
com])arisoii j:)urposos these latter fungi (cultures obtained froiu 
California) were inoculated in oranges, and re-isolated from the 
affected fruits. These organisms have been kept going in check 
series of cultures with the Australian pathogen for two seasons. 
In making isolations from leaves if^ was found that tissue taken 
from the bases of leaves showing lesions oidy on their apical portions 
readily produced the organism. This undoubtedly has a bearing ou 
tiie falling of the leaves while only visil)ly aft’ected at their tips. 
CULTURAL NOTES. 
P. hiheniaUs grows well on potato dextrose agai\ oat extract 
agar, })rime juice agar, French beau agar, dt‘xtrose peptone agai% 
prime juice and wheat meal. 
These media were prepared as under: — 
Potato Dextrose Agar, Potato, not peeled, washed and cut into 
3 inch cubes, 200 grams. Boiled gently in 1 litre of tap water 
in steamer foi^ 1 hour, strained through muslin, made up to 1 
litre with water, 20 grams dextrose and 25 grams agar added, 
and then autoclaved. 
Oat-Extract Agar. 50 grams crushed oats boiled gently in steamer 
for I hour in 300 c.c. tap water, strained through wire gauze, 
10 grams agar added and water to make 500 c.c., then auto- 
claved . 
Prune-Juice Agar. 12.5 grams of dried prunes, without stones, 
boiled ill 100 c.c. tap water foi 5 minutes, filtered, 7.5 grams 
agar and water to make iij) 500 c.c. added, then autoclaved. 
French-Bean Agar. 50 grams dried lieans pounded iu mortar, ])oiled 
30 minutes in 300 c.c. water, then strained through wire gauze, 
10 grams agar and water to make up 500 c.c. added, then 
autoclaved. 
Dextrose-Peptone Agar. Dextrose 10 grams, meat extract 2 grams, 
peptone 5 grams, sodium chloride 2.5 grams, agar 7.5 grams, 
autoclaved in 500 c.c. water. 
Wheat Meal. Wheat meal moistened with distilled water and auto- 
claved. 
Potato dextrose agar has been the most satisfactory medium 
tried and has been generally used. Both conidia and oospores are 
formed fairly freely in cultures after 10 days at temperatures of 
10-15° C. On prune juice agar and French beau agar conidia are 
formed scantily though oosp>ores are more plentiful. On oat extract 
agar and dextrose peptone agar and wheat meal only oospores are 
formed. In prune juice decoction no spores are formed. Conidia 
formed on agar media are remarkably constant in shape and similar 
to those occurring in nature though varying considerably in size- 
