1 98 Bailey . — Puccini a malvacearum and the Mycoplasm Theory . 
Culture. 
Spores in pustules on surface. 
Spores in submerged pustules. 
Germination. Type. 
Germination. 
Type. 
8. Sterile tap-water. 
G ood. Portion of pustule above 
water-level produced 
a great quantity of 
sporidia. Where in 
contact with the water 
at the edges it was 
mostly oidial. ' 
Good. 
All oidial. 
Series III. (May 1919.) 
Young pustules teased out under surface of distilled water in watch- 
glasses. 
Pustules from leaf of wild plant of Malva sylvestris showing rather 
heavy natural infection. 
Three cultures made. 
Rest clt. Germination in all three cases was poor, and two cultures 
never got beyond the production of very short undifferentiated germ tubes. 
In the remaining culture long thin tubes were produced, which in one or 
two cases divided up to form oidia. 
Series IV. (May- June 1919.) 
Two diseased leaves of a naturally infected wild plant of Malva 
sylvestris removed and supported in such a way that one half of each leaf 
was immersed in water whilst the other half remained exposed. 
The whole apparatus was covered with a bell-jar to ensure a moist 
atmosphere around the exposed portions of the leaves. 
The older-looking pustules were removed before starting the experi- 
ment 
Results. 
Leaf A. 
• Submerged portion. 
Moderately heavy infection. 10 pustules examined. Germination moderate and entirely 
oidial. 
Exposed portion. 
Leaf B. 
12 pustules examined. Germination excellent in 5 cases and 
moderate in remaining 7. 99 % typical 
sporidial. No typical oidia. 
■ Submerged portion. 
Very heavy infection, which 13 pustules examined. 4 had germinated very well and pro- 
had developed gradually. duced oidia only, except for a very 
few tubes resembling abortive pro- 
mycelia. 
7 germinated poorly, and produced 
only abortive tubes suggesting pro- 
mycelia which had failed to develop. 
1 failed to germinate. 
1 germinated well and produced spo- 
ridia in quantity. 
Exposed portion. 
12 pustules examined. 3 germinated poorly and produced 
sporidia only. 
9 germinated well, producing sporidia 
only. 
