10 
their development. It is often necessary, likewise, to he 
certain of the specific fungus causing a disease in order that 
accurate information may be obtained as to the effect of a 
• particular treatment, otherwise remedies may he and are 
condemned as useless, when they are really applied to some¬ 
thing very different from what was intended. 
Having determined that the specific disease is caused by 
a fungus, it is necessary if possible to fix its position among 
the 47,000 known species in order to profit by the experience 
of others, if the fungus and its effects have already been 
described, or, if new, to understand its relationship with 
those already known. While the determination of the 
fungus is the work of the specialist, the intelligent grower 
may employ some common name expressive of the salient 
characteristic of the disease, and by which it may be recog¬ 
nised. But since appearances are often deceptive, and very 
different diseases may be confounded under a common name, 
I have invariably given the scientific name of the fungus 
producing the disease along with the common name. This 
fixes the disease definitely, suggests lines of treatment based 
upon a knowledge of allied fungi, enables us to profit by the 
labours of previous investigators, and supplies material for 
future workers to consolidate and extend the knowledge 
already possessed. In the Report of the Proceedings of the 
Eleventh Annual Convention of the Association of American 
Agricultural Colleges and Experiment Stations (1897) it 
was recommended that, in speaking of fungi, the technical 
as well as the common name should always be given at least 
once in each publication, and this is a recommendation 
which I heartily indorse. 
As already noticed, the fungi are also described which, as 
far as known, are not the exciting causes of disease, but only 
appear when decay lias already set iu. This will at least 
prevent their being confounded with other fungus pests, 
which are really serious. 
In giving the relerences to the literature on the various 
diseases dealt with I have mainly confined myself to those 
published in Australia, on account of their being probably 
accessible to the growers, for whom this work is intended. 
But the various publications of the Division of Vegetable 
Physiology and Pathology of the United States Department 
of Agriculture may likewise he recommended, as well as 
Penzig’s elaborate work in “Aimali di Agricoltura, 1887,” 
together with the accompanying atlas of 58 plates. 
