ARTIFICIALLY SPREADING FUNGOUS DISEASES. 47 
vations. An examination of 100 leaves picked at random in 5 typical 
groves in Manatee County and 5 in Lee County in January, 1909, 
showed a ratio of 14 red-fungus pustules to 32 brown-fungus pustules 
in groves which had all been infected with both species for several 
years previous. In 9 of the 10 groves the total number of pustules 
of brown fungus counted exceeded the total number of red-fungus 
pustules. The single exception was a grove in which both species of 
fungous parasites were present in almost negligible amounts. In 
Orange County the brown fungus has also as a rule shown greater nat- 
ural efficacy than the red wherever the two species have both been pres- 
ent in the same grove and both have become well established. For 
example, in grove No. 1 of Tables II and IX the average number of 
red and brown fungus pustules per leaf was found to be 9.9 and 14.5, 
respectively, in December, 1909, and 3.7 and 52.9 in December, 1910. 
The natural efficacy of the yellow fungus against the cloudy-winged 
white fly is about the same, according to the authors' observations, 
as the natural efficacy of the red fungus against the citrus white fly. 
The fact that the red and brown fungi have shown very little adapta- 
bility to the cloudy-winged species has been mentioned elsewhere. 
HAVE THE FUNGOUS PARASITES INCREASED IN NATURAL EFFICACY SINCE THEIR FIRST 
DISCOVERY? 
The statement sometimes heard to the effect that the fungous dis- 
eases are more effective now than formerly is unquestionably without 
the slightest foundation, and it is unnecessary to devote any space 
to a discussion of the subject. 
ARTIFICIAL MEANS OF SPREADING FUNGOUS DISEASES. 
HISTORY OF WORK IN THIS LINE. 
Dr. H. J. Webber, who first discovered the red Aschersonia and 
the brown white-fly fungus, was also the first to undertake experi- 
ments with artificial methods of spread. 1 The methods tested included 
mixing the spores of the Aschersonia with water and spraying the 
infested leaves with an atomizer, hanging branches with pustules of 
the Aschersonia and brown white-fly fungus above branches in- 
fested with the white fly in groves where the fungous parasites did 
not occur, and transplanting young trees with parasitized white flies. 
The first method is reported to have failed to give satisfactory results. 
The second method was tested several times, but results were obtained 
in only one instance in the case of the red Aschersonia and once in 
the case of the brown, fungus. The season of the year when these 
tests were made is not stated. The transplanting of young trees 
seemed the most reliable method, and this was recommended in estab- 
i Bui. 13, Div. Veg. Phys. and Path., U. S. Dept. Agr., pp. 26 and 30, 1897. 
