Wheat Rust in Australia. 75 



NOTE 2. 



P. 14. Christman 1 , however, has clearly shown that two fertile cells or 

 swollen hyphal branches come into contact, and at the point of contact an 

 opening is formed by solution of the cell wall, and thus their contents mix 

 although the nuclei do not fusie. There is thus true sexual cell fusion with- 

 out the intervention of spermatia. 



NOTE 3. 



P. 24. Arthur 8 considers the sorus in such species as Puccinia bromina 

 and P. triticina to be compound and the modified hyphae which separate 

 the individual sori to form a stroma, hence they are not paraphyses, strictly 

 speaking. 



NOTE 4. 



P. 37. The origin of the aecidiospores as shown by Christman, 1 from the 

 fusion of sexual cells and the peridium from morphologically equivalent cells 

 disposes of the view that the aecidiospores may have been derived from 

 teleutospores. If, as Blackman suggests, the rusts originated from the red 

 algae, then the sexual product or aecidium would represent an early stage 

 in the history of the Rusts. 



NOTE 5. 



P. 43. Hooker, in his classical essay On the Flora of Australia (1859), 

 has a chapter on some of the naturalized plants, showing that even nearly 

 half a century ago, the chick-weed, knot-weed, scarlet pimpernel, daisy, 

 mallow, sweetbrier, and various other common plants had been introduced. 

 The groundsel, however, is not mentioned, and no doubt as trade increased 

 with other countries and exchange of products took place, the importation 

 of the seeds of weeds became common. 



NOTE 6. 



P. 62. Beauverie 1 has experimented with Botrytis cinerea, or grey rot, 

 and obtained, in sterilised soil, an attenuated form of fungus. He 

 infected soil liberally with this form, and grew plants therein from seeds 

 and cuttings perfectly free from the fungus, while plants not rendered 

 immune in this way perished. 



NOTE 7. 



P. 68. Kirk informs me by letter what he has already stated in his 

 Annual Reports that " Barberries are being largely usedl in New Zealand 

 for hedges, and, up to the present, I have never seen any sign of aecidia 

 of Puccinia graminis on them, although I have examined hundreds. It 

 would appear as if Puccinia graminis in Australia has lost the power of 

 forming aecidia on barberries." 



NOTE 8. 



P. 69. Bolley, 5 however, has announced that he found the uredospores 

 of Puccinia graminis successfully surviving upon dead leaves and straw, 

 even retaining their vitality when exposed to the drying winds of autumn, 

 and the intense cold of winter. * 



