ARTIFICIALLY SPREADING FUNGOUS DISEASES. 53 
hand the ends of the branches of the white-fly-infested tree can be 
momentarily immersed. This method is especially desirable where 
there are only a few trees to infect with the fungus and no satisfac- 
tory spray pump is available; also when only a few fungus-infected 
leaves can be obtained — as is frequently the case — and the greatest 
economy in the use of the water mixture is needed. The branches 
and twigs most heavily infested with the insects should be selected. 
For the dissemination of the brown white-fly fungus this is probably 
as satisfactory for general use as any method now known, the mixture 
being prepared as hereafter described in a slightly different manner 
than in the case of the mixtures of Aschersonia spores. 
The brushing method consists in dipping a whisk broom or a sub- 
stitute in the unstrained water mixture and brushing the under- 
side of the leaves of the trees to be infected as far as within reach 
and tlirowing the water by means of the brush against the under- 
side of the leaves higher up in the trees. Tins method, like the 
dipping method, can sometimes be employed with advantage in the 
case of the red and yellow Aschersonias and is especially useful in 
the case of the brown fungus, where unstrained solutions are naturally 
more desirable. 
MISCELLANEOUS EXPERIMENTS AND OBSERVATIONS. 
As infection was almost invariably secured in favorable seasons 
with fresh fungus material when spores of either the red or yellow 
Aschersonia were introduced by spraying, dipping, or brushing, it 
became apparent that the problem to be solved in connection with 
the introduction of fungi was not that of how to secure an infection, 
but by what means the ordinary infection secured by haphazard 
work could be increased by careful attention to the details. The 
results, however, of over 500 experiments conducted by the authors, 
together with those of growers, have been so variable that, at the. 
end of three years of experimentation, little has been added to our 
practical knowledge of how to insure satisfactory infections. These 
same statements apply to the brown fungus, although the securing 
of an infection with this fungus is at no time so certain as with the 
red or yellow Aschersonias. 
Results of straining water mixtures of spores through cloth strainers. — 
In straining the solution before spraying, the authors have found a 
fine-wire strainer (about one-sLxteenth-inch mesh) of most value. 
Under no circumstances should cotton cloths be used as strainers, 
for microscopic examination of strained and unstrained solutions 
shows that a large percentage of spores fails to pass through the cloth. 
Mr. E. L. Worsham found, as a result of 36. microscopic examinations 
of solutions strained and unstrained, that about one-third of the 
spores were lost when ordinary cheesecloth was used as a strainer. 
