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“ Wither-tip,” the shoots affected should be cut away during the 
pruning season, and destroyed by burning, since the minute spores 
may readily be carried by the wind or other agency and start the 
disease afresh. 
Hybridizing .—In the United States numerous experiments 
have been made in hybridizing Orange and other Citrus trees to 
secure, if possible, disease-proof varieties. “ Another important 
problem in Citrus culture which bas received attention during the 
past year is to secure a common Orange of good quality, with the 
loose, easily-removable rind of the tangiorine Orange, and also to 
secure sorts resistant to blight, and other diseases ” (Year-book of 
the United States Department of Agriculture, 1898). Other 
experiments iu hybridizing have been carried out to get a hardy 
Orange which will resist the severe frosts and freezes to which 
such fruits are subjected in Florida and California, and this 
has been attempted by crossing the common Orange with the 
Japanese hedge Orange or trifoliate Orange, which is a hardy sort, 
though of poor quality. This species is already grown in Aus¬ 
tralia, but being deciduous it might not prove quite suitable as a 
stock for evergreen trees. There are several native species, how¬ 
ever, which might well repay attention on the part of the 
cultivator. (Appendix 1.) 
In conclusion, it cannot be too strongly impressed on growers 
that co-operation in dealing with plant diseases is absolutely 
essential for completo success. Just as thistle-down may spread 
from a neighbouring dirty field to a clean one, so the spores of a 
parasitic fungus may be carried by the wind or other agency to 
an orchard where every reasonable precaution is taken to guard 
against disease, and thus the efforts to check disease may be 
neutralized or, at any rate, rendered more difficult. Prevention is 
better than cure, and co-operation renders it sure. 
It may seem rather discouraging to the Citrus-grower that he 
may have so many fungus diseases to fight, but if the danger which 
threatens him leads to cleaner cultivation and to a regular system 
of treatment which will not only prevent disease, but improve 
the quantity and quality of the fruit, then the knowledge of the 
existence of such formidable foes will have served as an incentive 
to progress and a spur to exertion. 
EXPLANATION OF TERMS. 
Ascics (plural Asci) is the little bag containing sporidia en¬ 
closed within a larger case or perithecium. 
Bacteriosis is the name given to the class of diseases produced 
by the minute micro-organisms generally known as bacteria. 
