119 



plantation so as to admit plenty of sunlight, (4) good culture and 

 the application of suitable manure as a top-dressing. The manure 

 should not be of a highly nitrogenous nature. 



With regard to the application of Bordeaux mixture it may 

 be said that it will certainly prevent the germination of all the spores 

 with which it comes in contact, but it will be necessary to make the 

 applications frequent if the result is to be beneficial, for the spores 

 are produced in abundance and with rapidity, so that two days after 

 an application there may be another crop of spores ready to produce 

 further infection. The weaker form Bordeaux mixture will not injure 

 the Sunflower plants, and if the mixture be properly made an almost 

 unlimited quantity of it may be applied. The suggestion is to apply 

 the mixture every two to three days, the best time of day being 

 evening or early morning. * 



From time to time for a number of years inquiries have reached the 

 writer, showing that more complete information on the various genera 

 of Rust-fungi would be acceptable to a considerable number of readers 

 of this Gazette. There is no Australian work dealing comprehensively 

 with this subject. The insertion in these letters of copies of a number 

 of classical illustrations from the works of Tulasne, de Bary and 

 Plowright may do some little service in this direction. The originals 

 are for the most part in comparatively inaccessible scientific publi- 

 cations. All the most important genera of the Uredinese, or Rust- 

 fungi, are illustrated and explained, the explanation of each plate 

 being placed opposite. (See final plates.) 



Smut of the Prairie Grass. 



The season of 1903, following on a succession of droughty years, 

 and being itself rather a moist season, gave rise to some unusual 

 fungus developments. One of these was the 

 appearance of smut on Prairie Grass. The 

 species of smut found on this grass is already 

 known in this State, though not previously 

 seen on this species of grass. It is a species 

 of smut reported from various parts of the 

 world on grasses of the genus Bromus. It Fig. 130 Spores of the smut 

 is not generally supposed to do much harm. ^^SSTaS 1 " 1 Us 



It has appeared in one instance in this State 



as a marked attack on Prairie Grass self-sown on a paddock formerly 

 remarkable for its crops of smutty maize, and the question arose 

 whether the two had any connection. As the two smuts, I hat. of 

 maize and that of the Brome grasses, are different species, the 

 occurrence in the same paddock in successive years, can be looked 

 upon only in the light of a coincidence. It may well be that the 

 particular paddock is one in which the conditions are very suitable 

 for the growth of smut fungi. It may be safely assumed that the 

 conditions, other than the host-plant condition, required by two smuts 

 so like each other as the smuts of maize and Brome grass, would be 

 similar, and no doubt if maize had been grown in 1903 in this 

 paddock the smut proper to it would have made its appearance. 



