Hick : Puccinia graiiinis. 



135 



-were rapidly but thoroughly examined, and found free from TJredo. The 

 glasses were replaced, and the plants re-examined on the 30th day. 

 These were then finally removed and the plants thoroughly examined, 

 but no trace of TJredo found upon either the infected or upon the 

 check plants." 



The TJredo mentioned in the quotation is TJredo lineorh^ which is 

 synonymous" with Trichobasis rubigo-r,era. 



Such experiments undoubtedly possess a certain amount of value, 

 but, however great the per-centage in favour of either view, could 

 scarcely be accepted as positive proof. The spores of all the forms 

 germinate readily, and although difficulties would be met in tracing 

 -every change, yet those difficulties are not insurmountable, and must 

 -be met if real work that can be accepted as conclusive is attempted. 



The development of other forms of fungi, that are injurious to fir 

 trees, has been followed by allowing the spores to develop in turpen- 

 tine ; and experiments persevered in would undoubtedly reveal some 

 artificial medium in which the present plant could be followed through 

 all its stages. It has been suggested that the fungus, in some form or 

 other, is present in the grain when sown, and developes along with the 

 latter; and Mr. Plowright's experiment No. 13 would seem to coun- 

 tenance this view. Puccinia spores that are a year old germinate best ; 

 the other spores germinate at once. 



An additional experiment, not included in the thirteen mentioned 

 by Mr. Plowright, is also given in " Grevillea," as follows : — " Six 

 wheat plants were infected with the spores of TJredo linea?is at 4 p.m. 

 on the 13th August. On the 24th they were all simultaneously 

 .affected with TJredo, showing that the TJredo had reproduced itself in 

 -eleven days." In this experiment, Mr. Plowright evidently considers 

 the appearance of the TJredo as the result of inoculation ; but if so, 

 TJredo produced TJredo, and not (as one would expect) Puccinia. But 

 perhaps it might be said that the same form is reproduced for several 

 times in succession, or that the Puccinia spores appear from the TJred& 

 mycelium at a later stage. 



PUCCINIA GRdMINIS. 

 By Thos. Hick, B.A., B.Sc,, &a 



At the last annual meeting of the Yorkshire Naturalists' Union, it 

 was suggested by Prof. Williamson that the botanical section should 

 endeavour to work out afre<sh the life-history of Puccinia yraminis, whose 



