214 PUCCINIA DIGRAPHIDIS. 



cisuial Uredine, and that the host which bears the uredo and 

 teleutospores is Phalaris arundinacea. Below is a condensed 

 account of my observations. 



On June 13th, 1889, I applied germinating spores of the 

 iEcidium to the leaves of Convallaria majalis, Molinia carulea, 

 Dactylis glomerata, and Phalaris arundinacea. When infected the 

 plants were in a healthy condition, and each plant was dealt with 

 in precisely the same way and covered by a bell-glass. 



The first indication of a result was on June 21th, 1889, when 

 faint spots began to appear on the leaves of Phalaris arundinacea, 

 from which developed, on June 29th, small reddish sori of uredo- 

 spores. By July 4th several leaves were rusted over with uredo, 

 and on July 17th the first black sorus of teleutospores was evident 

 amongst the uredo. On Aug. 9th a great many of the black sori 

 were conspicuous on the withering leaves. 



Not the least result followed on the Dactylis, Convallaria, or 

 Molinia; and I may also state that Mr. C. B. Plowright, of King's 

 Lynn, infected Phragmites communis with spores of the a3cidium I 

 sent him, about the same time, but without result. With germi- 

 nating uredospores — produced as above — I infected, on July 8th, 

 two isolated plants of PJudaris arundinacea; both had developed 

 uredo on July 24th, and on Aug. 11th the black sori of teleuto- 

 spores began to show, which by Sept. 14th were numerous. During 

 September I paid a visit to Bowness, Westmoreland, — a locality 

 where the secidium was abundant on Convallaria the previous 

 spring, — and found no trace of uredo or teleutospores on Phragmitis, 

 Molinia, or Convallaria, but Phalaris arundinacea was infested by a 

 Puccinia with here and there uredo still evident, which on micro- 

 scopical examination were very similar to those I had produced 

 artificially, and in some respects not unlike the teleutospores of 

 Puccinia sessilis and P. phalaridis, both species of which occur on 

 Phalaris arundinacea. 



A number of leaves containing the teleutospores were collected 

 and placed under a bell-glass in a corner of my garden, where they 

 remained undisturbed throughout the winter. Later on (Oct.), 

 plants bearing artificially-produced teleutospores were similarly 

 protected by a bell-glass and kept apart. 



During December, 1889, and January, 1890, several attempts 

 were made to cause the teleutospores to germinate, by placing a 

 number of sori in water, and keeping them in a temperature from 

 60° F. to 70° F., but without success. 



The first signs of germination were on April 23rd, when a short 

 promycelium was seen emitting from two of the teleutospores. 

 Three days later germination was more active, and at the end of 

 April I commenced the following experiments, which had been 

 carefully arranged beforehand : — 



1. April 30th. — Actively germinating teleutospores from Pha- 

 laris arundinacea were applied to the leaves of Convallaria and 

 Allium ursinum. On May 8th spermogonia were visible on Con- 

 vallaria, which were succeeded by secidiurn cups, many of the 



